> ^5°. ♦♦"% & <; »,1 * ♦♦*% -4. . . * **0* .0* ,v o • » V «o- -/ V -o *^T* <v »4> »* v \ ^% - ° " " 0><* ^°\ ,^ v 'of V'; 1 ** v \ 1 v*<<; % ,0 O * ( 7T. A. ^ o . » r ^o^ /x '•«• .♦♦*% « y -0 \» -S ■^- > %^ ijk ; /^ «i?> o ^°^ ^iiiK ; ^°** yassv *°-v vssep; *«°* -life' yS "V ^tiatey* /,•£;%% ^*££k°» / •" >d» :«f&- *bi* --calk- *w «P^ <>u<v >--v <£ ^ ^ 4 Q^ W .-isfifel-. V>* 4? % - o X.-^ii-% £*X&k°» ^<^/^ /*- 4 0. ,S^ n •%, ^°^ C U ♦' P v > •» o "bv* * -<o. ♦ y -v. IC 8838 Bureau of Mines Information Circular/1981 Polychlorinated Biphenyls: Regulations and Substitutes A Compliance Manual for the U.S. Mining Industry By R. A. Westin, R. P. Barruss, B. Woodcock, and R. L. King UNITED STATES DEPARTMENT OF THE INTERIOR Information Circular 8838 Polychlorinated Biphenyls: Regulations and Substitutes A Compliance Manual for the U.S. Mining Industry By R. A. Westin, R. P. Barruss, B. Woodcock, and R. L. King UNITED STATES DEPARTMENT OF THE INTERIOR James G. Watt, Secretary BUREAU OF MINES # This publication has been cataloged as follows Polychlorinated biphenyls: Regulations and substitutes. (Information circular - Bureau of Mines ; 8838) Includes bibliographical references. Supt. Docs no.: I 28.27:8838. 1. Polychlorinated biphenyls— Handbooks, manuals, etc. 2. Elec- tricity in mining— Handbooks, manuals, etc. I. Westin, Robert A. II. Series: United States. Bureau of Mines. Information circular ; 8838. TN295.U4 [T55.3.H3] 622s [363. 1'79] 80-607190 CONTENTS Page Abstract 1 Introduction. 1 Background 3 PCB's used in the U.S. mining industry 4 General requirements 6 Recordkeeping (40 CFR 761.45) 6 Marking (40 CFR 761.20) 7 Containers for PCB's (40 CFR 761.42) 8 Storage (40 CFR 761.42) 9 Spill cleanup [40 CFR 761.10(d)] 9 Other information 10 Other regulations 10 Decontamination (40 CFR 761.43) 11 Transportation [40 CFR 761.42, 761.20(b)] 11 Disposal (40 CFR 761.10) 12 Askarel transformers 12 Uses of askarel transformers in mining 13 Machine mounted 13 Underground 14 Surface 15 Number of askarel transformers used in U.S. mines 15 How to identify an askarel-filled transformer 17 EPA requirements for PCB (askarel) transformers 18 Precautions for continued use. 20 Significance of water 20 Decision guide 21 Dikes 24 Berms 27 Fences and vehicle barriers 28 Curbs and doorway dikes 29 Emergency foam packs 29 Special problems 29 Mobile mining machinery 30 Relocation of transformers 31 Retrof illing 31 Non-PCB replacement transformers 32 Characteristics of non-PCB replacement transformers 33 Oil-filled transformers 33 Silicone transformer liquid 34 High-fire-point transformer liquids 34 Open air-cooled transformers 35 Sealed gas-filled transformers 36 Cast coil transformers.... 37 Mining machinery transformers 37 Relative costs of non-PCB replacement transformers 38 Summary — considerations in choosing an alternative to PCB transformers 39 PCB-contaminated transformers ♦ 40 11 CONTENTS— Continued Page PCB capacitors 42 Uses of PCB capacitors in the mining industry 42 How ~tp identify PCB capacitors 42 Requirements for PCB capacitors 43 Precautions for continued use 45 Substitutes for PCB capacitors 45 Underground mining machinery 46 Use 46 Identification 46 EPA requirements 47 Recommended precautions for continued use 48 Emergency spill response 49 Non-PCB replacement equipment 49 Electromagnets 49 Use 49 Identification 50 EPA requirements 50 Recommended precautions for continued use 51 Emergency spill response 52 Non-PCB electromagnets 52 Heat-transfer fluids 53 Use 53 EPA requirements 53 Recommended precautions for continued use 55 Emergency spill response 55 Non-PCB heat-transfer fluids 56 Hydraulic fluids 56 Use 56 Identification 56 EPA requirements 56 Non-PCB hydraulic fluids 57 Waste oil 57 EPA requirements 57 Recommendations 57 Appendix A. — Outline of PCB spill response guide 58 Appendix B. — Water-only drainage system 59 ILLUSTRATIONS 1. Toxic Substances Control Act 5 2. Typical transformer and switch gear on concrete mounting pad with steel dike installed 24 3. Shop preparation of 6- by 3.5-inch angle-steel dike edge, including mitre-cut and ground ends and holes to be drilled 25 4. Corner joints — 2- by 2-inch steel angle 25 5. View of corner joint, top view detail of corner joint, and section through dike 26 ILLUSTRATIONS— Continued iii Page 6. Side view and pictorial view from top of the water-only drainage system 26 7. Schematic diagram of basic parts and dimensions of an extended mounting pad 27 8. Vehicle barrier suitable for protection of an askarel transformer located in a parking lot or next to a street 28 B-l. Copper plumbing pipe with cap and fitting 59 B-2. Valve face 59 B-3. Bottom view of valve face 60 B-4. Two pieces brazed on valve face 60 B-5. Rectangular piece of copper for "guard plate" 60 B-6. Brazing of "guard plate" to main body of valve 61 B-7. "Valve rest" 61 B-8. Bearing support holes and hole-locating jig 62 B-9. Silicone rubber for "flapper valve" 63 B-10. "Flapper valve" as made by method (a) 63 B-ll. Mold half for pattern of "flapper valve" 64 B-12. Hinge support for flapper valve 64 B-13. Pipe flange 65 B-14. Fitting of drain valve and flange into inside of dike 65 B-15. Screen covering valve system..... 66 TABLES 1. Manufacturers and trade names of PCB's 3 2. Summary of askarel transformer data gathered during visits to mines 16 3. Extrapolated estimates of numbers of askarel transformers in various mining segments 17 4. Cost comparisons of oil-filled versus other transformer designs intended for hazardous locations 39 5. Quantity of PCB's in mining machinery 46 4 POLYCHLORINATED BIPHENYLS: REGULATIONS AND SUBSTITUTES A Compliance Manual for the U.S. Mining Industry by R. A. Westin, 1 R. P. Barruss, 2 B. Woodcock, 3 and R. L. King* ABSTRACT Polychlorinated biphenyls (PCB's) have been widely utilized as fire- resistant dielectric coolants in electrical equipment used in mining applications, including transformers, capacitors, electric motors, and elec- tromagnets. In addition, PCB's have been used in hydraulic fluids and heat- transfer fluids and are present in many oil-filled transformers. The U.S. Environmental Protection Agency (EPA) recently banned the manufacture of PCB's and equipment using PCB's, and imposed strict requirements on the con- tinued use and disposal of existing PCB equipment. This manual discusses the EPA requirements, suggests ways to decrease the risks resulting from continued use of PCB equipment, and surveys the non-PCB equipment that is available as replacements for the PCB electrical equipment presently used in mines. INTRODUCTION The U.S. Environmental Protection Agency (EPA) recently banned the manu- facture of new equipment containing polychlorinated biphenyls (PCB's) and established stringent requirements on the continued use and disposal of exist- ing equipment containing PCB's. These regulations apply to all PCB's in the United States, Puerto Rico, Virgin Islands, and U.S. Pacific territories. All PCB's are regulated, including those in use in equipment in surface and under- ground mines. PCB's have been the basis for fire-resistant askarel liquids used in transformers and capacitors and have been used in various other applications in the mining industry. A contract (J01 77046) was awarded by the U.S. Depart- ment of Interior, Bureau of Mines, to Versar, Inc., Springfield, Va., to study (1) how to comply with EPA regulations and (2) how to select replacements for equipment that contains PCB's. The information in this manual addresses these issues. 1 Senior chemical engineer, Versar, Inc., Springfield, Va. 2 Senior mechanical engineer, Versar, Inc., Springfield, Va. %echanical engineer, Versar, Inc., Springfield, Va. ^Technical project officer, Pittsburgh Research Center, Bureau of Mines, Pittsburgh, Pa. A necessary supplement to this manual is a copy of the EPA regulations on PCB's. Reprints of the PCB Ban Regulation (published in the May 31, 1979, Federal Register) are available from EPA, along with a list of the EPA- approved PCB Disposal Facilities. Additional background information on the regulation is also available in the EPA Support Document to the PCB Ban Regu- lation. Te, obtain copies of all of these reports, call (toll-free, 800-424-9065, or in Washington, D.C., local 554-1404) or write the Office of Industry Assistance, Office of Toxic Substances TS-799, U.S. Environmental Protection Agency, 401 M St., S.W., Washington, D.C. 20460. Note for potash and phosphate mines and mills : On May 9, 1980, the EPA proposed the following regulations: " except for small PCB capacitors and except for facilities manufacturing anhydrous liquid ammonia, the use or stor- age of PCB items, as defined in sec. 761.2 (x), at facilities manufacturing, processing, or storing bulk, unpackaged fertilizer or agricultural pesticides is prohibited" (Federal Register, page 30993). This regulation has not yet been promulgated, nor is it known whether it will affect the use of PCB's in potash and phosphate mines or mills. For advice as to whether this will affect the continued use of PCB's at your installation, call (toll-free, 800-424-9065, or in Washington, D.C, local 554-1404) or write the Office of Industry Assistance, Office of Toxic Substances TS-799, U.S. Environmental Protection Agency, 401 M St., S.W., Washington, D.C. 20460. Other available information : This report does not go into much detail about the health and environmental effects of PCB's or the chemicals now being used as substitutes for PCB's. The following reports cover these technical areas; the NIOSH Criteria Document is particularly recommended for its discus- sion of health issues if you are going to service PCB equipment or clean up PCB spills. National Institute for Occupational Safety and Health. Criteria for a Recommended Standard. . .Occupational Exposure to Polychlorinated Biphenyls (PCB's). Pub. 77-225, September 1977; available from U.S. Government Printing Office, Washington, D.C. U.S. Environmental Protection Agency. Assessment of the Use of Selected Replacement Fluids for PCB's in Electrical Equipment. Rept. EPA 560/6- 77-008, March 1979; available from National Technical Information Service, Springfield, Va. , PB 296 377. Interdepartmental Task Force in Polychlorinated Biphenyls. Polychlorinated Biphenyls and the Environment. 1972; available from National Technical Information Service, Springfield, Va. , Rept. NTIC COM-72-10419. Versar, Inc. PCB's in the United States: Industrial Use and Environmental Distribution. Feb. 25, 1976; available from National Technical Information Service, Springfield, Va., PB 252 012. Background Polychlorinated biphenyls (PCB's) are a class of chemicals that have been used since 1930 as the basis for nonflammable dielectric liquids in electrical equipment such as transformers and capacitors and as a component of some heat- resistant, heat-transfer, and hydraulic fluids. PCB's were manufactured in the United States from 1930 through 1977, primarily by Monsanto Industrial Chemicals Co., 5 which marketed various mixtures of PCB's under the trade name Aroclor. Mixtures of PCB's and other chemicals were marketed by Monsanto and by other companies under a variety of trademarks for different applications as described later in this report. PCB's have also been manufactured in Europe and Japan, as listed in table 1. TABLE 1. - Manufacturers and trade names of PCB's Manufacturer Bayer Caf faro Caf faro Caf faro Chemko Geneva Industries.. Kanegaf uchi , Monsanto Monsanto Monsanto Prodelec. . « Prodelec ., Sovol , Country Germany Italy Italy , Italy Czechoslovakia United States Japan United Kingdom and United States. United Kingdom and Japan. . United Kingdom and Europe. France France U.S.S.R Trade name Clophen. Fenclor . DK. Inclor. None. Not Known. Kennechlor. Aroclor. Santotherm FR. Pryoclor. Phenoclor. Pyralene. None. PCB's were identified as a serious and widespread environmental pollutant in 1968, leading Monsanto to voluntarily limit the sales of PCB's to "totally enclosed" capacitor and transformer applications after 1972. Limitations on the presence of PCB's in food were established by the U.S. Food and Drug Administration (FDA) in 1973. In 1977, the EPA banned the discharge of PCB's into the water effluents from PCB manufacturers, capacitor manufacturers, and transformer manufacturers. A review of the uses and environmental distribu- tion of PCB's in 1975 indicated that more than half the 1.5 billion pounds of PCB's that had ever been manufactured in the United States were still in use in electrical equipment and that only about 10 percent of the total PCB's had entered the environment. Even this relatively low environmental load of PCB's was sufficient to cause the PCB concentration in some freshwater fish to exceed the limits set by the FDA. The resulting ban on the sale of contami- nated fish essentially ended commercial fishing on the Hudson River, in much of the Great Lakes, and in a number of other freshwater lakes and rivers. 5 Use of brand names is for identification purposes only and does not imply endorsement by the Bureau of Mines. The environmental and health problems associated with exposure to PCB's result from the same properties that make these chemicals useful in industrial and electrical applications: PCB's are very stable chemically, are soluble in organic solvents, and are almost insoluble in water. PCB's that are released to the environment do not degrade, but accumulate preferentially in the fat of micro-organisms and bioaccumulate in the food chain. As a result, the concen- tration of PCB's in fish may be 1 million times higher than in the water that the fish lives in. Many organic compounds that are insoluble in water are excreted by birds and mammals by being converted to water-soluble compounds by powerful enzymes in the liver. High concentrations of water-insoluble chemi- cals in the body will cause the liver to increase the production of these enzymes. Unfortunately, PCB's are immune to attack by these enzymes and so are not excreted but instead build up in the body, causing the liver to con- tinue its increased production of the enzymes. Although the enzymes do not react with the PCB's, they will react with various hormones, and the increase in enzyme levels in the body activated by PCB concentration results in decreased levels of these hormones, which causes decreased shell thickness in bird eggs and reproductive problems in mammals. PCB's do not appear to be a direct cause of cancer, but the enzyme changes caused by exposure to PCB's may make the body more susceptible to the effects of low levels of direct carcin- ogens found in cigaret smoke and in other manmade environmental pollutants. Ingestion of relatively large quantities of PCB's (on the order of 1 gram) can cause liver damage, skin problems, and other acute health effects. In 1976, the U.S. Congress passed the Toxic Substances Control Act, which gave the EPA wide authority to control the production and use of chemicals in the United States. Section 6(e) of this act mandated a complete ban on the manufacture, processing, distribution in commerce, and use of PCB's and required the EPA to establish requirements for the marking and disposal of PCB's in use (fig. 1). The act also allowed the EPA to authorize the contin- ued use of PCB's after July 1, 1979, if the agency found that such use did not present undue risk to human health or the environment. The EPA promulgated the required Disposal and Marking Regulations for PCB's on February 17, 1978, and on May 31, 1979, promulgated the PCB Ban Regulations, which authorize cer- tain continued uses of PCB's and specify the conditions that must be met by those who continue to use PCB's. PCB's Used in the U.S. Mining Industry The EPA regulations on the marking, processing, use, and disposal of PCB's will affect the following equipment and activities in the mining industry: 1. Askarel transformers: Marking, maintenance, disposal, spill cleanup, recordkeeping, storage for disposal. 2. Oil-filled transformers: Disposal of oil. 3. Capacitors: Marking, disposal, spill cleanup, recordkeeping, storage for disposal. Section 6(e), Toxic Substances Control Act PUBLIC LAW 94-469— OCT. 11, 1976 90 STAT. 2025 "Totally enclosed manner." (e) Polychlorinated Biphenyls. — (1) Within six months after Rules, the effective date of this Act the Administrator shall promulgate rules to — (A) prescribe methods for the disposal of polychlorinated biphenyls, and (B) require polychlorinated biphenyls to be marked with clear and adequate warnings, and instructions with respect to their processing, distribution in commerce, use. or disposal or with respect to any combination of such activities. Requirements prescribed by rules under this paragraph shall be con- sistent with the requirements of paragraphs (2) and ('A). (2) (A) Except as provided under subparagraph (B), effective one year after the effective date of this Act no person may manufacture, process, or distribute in commerce or use any polychlorinated biphenyl in any manner other than in a totally enclosed manner. (B) The Administrator may by rule authorize the manufacture, processing, distribution in commerce or use (or any combination of such activities) of any polychlorinated biphenyl in a maimer other than in a totally enclosed manner if the Administrator rinds that such manu- facture, processing, distribution in commerce, or use (or combination of such activities) will not present an unreasonable risk of injury to health or the environment. (C) For the purposes of this paragraph, the term "totally enclosed manner" means any manner which will ensure that any exposure of human beings or the environment to a polychlorinated biphenyl will be insignificant as determined by the Administrator by rule. (3) (A) Except as provided in subparagraphs (B) and (C) — (i) no person may manufacture any polychlorinated biphenyl after two years after the effective date of this Act, and (ii) no person may process or distribute in commerce any poly- chlorinated biphenyl after two and one-half years after such date. (B) Any person may petition the Administrator for an exemption Petition for from the requirements of subparagraph (A), and the Administrator exemption, may grant bv rule such an exemption if the Administrator finds that— (i) an unreasonable risk of injury to health or environment would not result, and (ii) good faith efforts have been made to develop a chemical substance which does not present an unreasonable risk of injury to health or the environment and which may be substituted for such polychlorinated biphenyl. An exemption granted under this subparagraph shall be subject to Terms and such terms and conditions as the Administrator may prescribe and conditions, shall be in effect for such period ( but not more than one year from the date it is granted) as the Administrator may prescribe. (C) Subparagraph (A) shall not apply to the distribution in com- merce of any polychlorinated biphenyl if such polychlorinated biphenyl was sold for purposes other than resale before two and one half vears after the date of enactment of this Act. (4) Any rule under paragraph (1), (2)(B), or (3)(B) shall be promulgated in accordance with paragraphs (2), (3), and (i) of sub- section (c). (5) This subsection does not limit the authority of the Adminis- trator, under any other provision of this Act or any other Federal law. to take action respecting any polychlorinated biphenyl. FIGURE 1. - Toxic Substances Control Act. 4. Electric motors (PCB-filled as used on Joy Manufacturing model CU43 and 9CM continuous miners and 14BU10 loaders): Continued use, maintenance, disposal, spill cleanup. 5. Separator electromagnets (PCB-filled): Marking, maintenance, disposal,^spill cleanup. 6. Hydraulic and heat-transfer systems (that ever contained a PCB-based fluid): Marking, maintenance, use, disposal, spill cleanup. 7. Waste oil: Disposal, use. 8. Transportation of any PCB's or PCB equipment. 9. Storage of any PCB's or PCB equipment. 10. Recordkeeping: Required if you have any PCB transformers, more than 45 kg (99.4 lb) of PCB's in containers, or more than 49 large PCB capacitors. GENERAL REQUIREMENTS It was the intent of Congress to ban the use of PCB's and thereby prevent the entry of PCB's into the environment. To continue use of PCB's in those applications authorized by the EPA, the requirements specified by the regula- tions must be met. EPA has the authority to enforce these requirements by performing compliance inspections wherever PCB's are used, including in mines. Violations of the regulations can result in fines of up to $25,000 per viola- tion per day. Willful violation of the regulations can result in additional criminal action against the responsible people, with a possible penalty of a $25,000 fine and 1 year in jail. EPA is serious about keeping PCB's out of the environment. Continued use or handling PCB's or PCB equipment after July 1, 1979, under the authoriza- tions granted by the EPA, requires compliance with the following general requirements and the specific requirements that apply to specific kinds of PCB equipment. Recordkeeping (40 CFR 761.45) Special recordkeeping requirements are specified in Annex VI of the PCB regulations. Maintenance of these perpetual PCB inventory records is required for each facility that has in use or in storage — 45 kg (99.4 lb) of PCB's or PCB contaminated material in containers; One or more PCB transformers; 50 or more large (3 lb liquid) PCB capacitors. In addition, an annual report must be prepared by July 1 of each year, summarizing the changes in PCB use during the previous year. EPA will use these records when it performs compliance inspections, and will consider the lack of records or discrepancies in the records as evidence of lack of intent to comply with the regulations. The records will have to be kept until 5 years after the last PCB's have been removed from the facility. The EPA regulations are very specific as to the kinds of information that must be kept. Any capacitor that contains 3 lb of PCB's must be considered to be a "large capacitor" for purposes of labeling, disposal, and recordkeeping. To estimate the weight of PCB's in a capacitor, assume that 20 percent of the volume of the can is filled with PCB's weighing 11.4 lb per gal: Capacitor can volume (cu in) x 0.01 = lb PCB A "large capacitor" would be any capacitor having a total volume exceeding 300 cu in. Marking (40 CFR 761.20) The EPA requires that special 6-inch-square yellow labels (described in Annex V of the regulations) be applied to practically everything that has more than 50 ppm PCB's except small capacitors (less than 3 lb PCB's) and oil- filled transformers (below 500 ppm PCB's). Labels must be applied to equip- ment that contains PCB's, including transformers, large capacitors operating above 2,000 volts, contaminated hydraulic and heat-transfer systems, electro- magnets, electric motors, cans and drums used to store PCB's and contaminated material, storage areas, and trucks carrying PCB transformers or more than 45 kg (99.4 lb) of PCB's or PCB-contaminated material. The only exception to applying the label directly to the item applies to large capacitors mounted on the top of a power pole or behind a fence at a substation; a single label may be applied to the pole or fence if records are adequate to identify which of the capacitors contains PCB's. Large PCB capacitors operating below 2,000 volts do not have to have a label until they are removed from service, but it would be a good idea to label them now to identify them as PCB items. It is advisable to keep 10 or 20 extra labels on hand to be applied to drums used to store used transformer oil, clean up spill material, contaminated rags, etc. Pressure-sensitive labels meeting EPA requirements may be purchased from a number of companies, including — Label Master W.H. Brady Company 6001 North Clark St. 727 West Glendale Ave. Chicago, 111. 60660 Milwaukee, Wis. 53209 312-973-5100 414-332-8100 5 This list is for reference only, and does not imply endorsement by the Bureau of Mines or the U.S. Environmental Protection Agency. Containers for PCB's (40 CFR 761.42) Containers used to store liquid PCB's must comply with one of the following requirements: (1) 49 CFR 178.80 — specification 5 without removable head. (2) 49 x CFR 178.82 — specification 5B without removable head. (3) 49 CFR 178.116— specification 17E. Any container that meets the requirements described in these specifica- tions will be marked with D0T-5-, D0T-5B-, or D0T-17E-. There may be addi- tional markings, but they do not affect the suitability of the containers. If the liquid PCB's are to be stored in containers larger than permitted in the above specifications, the following requirements must be met: 1. The containers must be designed, constructed, and operated in compli- ance with Occupational Safety and Health Standards, 29 CFR 1910.106. The specification for flammable and combustible liquids is included in Sec- tion 1910, Title 29 of the Code of Federal Regulations. To obtain a copy, call (202-783-3238) or write the U.S. Government Printing Office, Washington, D.C. 20402. 2. Either (a) the container shall be kept in a storage area that meets the requirements described or (b) a Spill Prevention, Control, and Counter- measures Plan (SPCC), as described in 40 CFR 112, must be prepared and imple- mented. (Amendment of SPCC plans by the Regional Administrator, 40 CFR 112.4, does not apply. The following report describes in detail how to prepare a sat- isfactory SPCC plan for PCB's; to obtain a copy, call (415-961-9043) or write the Electric Power Research Reports Center, Box 50490, Palo Alto, Calif. 94303. Electric Power Research Reports Center. Disposal of Polychlorinated Biphenyls (PCB's) and PCB-Contaminated Materials. V. 2. Suggested Procedure for Development of PCB Spill Prevention Control and Countermeasure Plans. V. 3. Example Preparation of a Utility PCB Spill Prevention Control and Countermeasure Plan. Palo Alto, Calif., 1980. Any container used to store rags, contaminated soil, or other nonliquid PCB's must comply with one of the following: (a) 49 CFR 178. 80— specif ication 5. (b) 49 CFR 178.82— specification 5B. (c) 49 CFR 178.115— specification 17C. (d) Any container larger than the 55-gal size given in the above specification shall provide as much protection against leaking and be of the same strength and durability as the containers described. Containers that meet either a, b, or c above will be labeled either D0T-5-, D0T-5B-, or D0T-17C-. With the exception of the specifications from the Occupational Safety and Health Standards, all of the above specifications are included in Title 49 of the Code of Federal Regulations, Transportation (parts 100-199). To obtain a copy, call (202-783-3238) or write the U.S. Government Printing Office, Wash- ington, D.C. 20402. Storage (40 CFR 761.42 ) The basic requirement is that PCB ' s be stored in special storage areas in buildings that are located above the 100-year flood water elevation and that the storage areas be diked and have impervious floors with no drains. PCB's put into storage before January 1, 1983, must be removed and disposed of by January 1, 1984. PCB's put into storage after January 1, 1983, may not remain in storage for more than 1 year. The items in storage must be checked every 30 days to insure that they are not leaking PCB's. Temporary storage outside the special storage areas is allowed for cer- tain nonleaking equipment and containers for a period of 30 days. Nonleaking large capacitors and drained askarel transformers may be stored adjacent to the special area until January 1, 1983. The regulations also specify the types of drums and tanks that can be used to store PCB liquids and contami- nated solids. The storage requirements are complicated and probably expensive. Most of the problems can be avoided by disposal of any PCB's within 30 days after they are removed from service. However, there are no incinerators presently approved for PCB liquids, so askarel removed from transformers and other con- taminated liquids must be stored in compliance with these regulations until EPA approves an incineration facility. Spill Cleanup [40 CFR 761.10(d)] EPA regulations require that all material contaminated with PCB's in con- centrations above 50 ppm by weight (for example, 1 lb of PCB's in 10 tons of dirt or other material be picked up, drummed, and disposed of in specially approved facilities. This is potentially the most expensive provision of the regulations. The cost of cleaning up PCB spills onto dirt or major machinery can be high. The cost of cleaning up a PCB spill that has entered the water can be horrendous. The potential cost of spill cleanup will justify work per- formed now to limit the extent of PCB spills and may justify replacing PCB equipment if there is much risk of PCB's entering water from failed equipment. Immediate response to PCB spills should be based on three major principles: (1) Minimize human exposure to PCB's: Disconnect the power from electri- cal equipment to stop the boil-off of PCB's; provide workers with protective gloves and clothing and, if necessary, breathing apparatus. 10 (2) Prevent PCB's from entering water: Soak up spilled PCB's with straw, rags, sawdust, dirt, or anything else that is available; throw up temporary dikes to minimize the spread of spilled liquid. (3) After the spill is under control, contact experts to decide on cleanup and disposal procedures. The PCB labels that are required on all PCB equipment give the toll-free number of the U.S. Coast Guard National Response Center (800-424-8802). Personnel at this number will give the names and tele- phone numbers of EPA personnel at the appropriate regional office who in turn will be able to give guidance in the cleanup procedure. In the event of a major spill into water, the Coast Guard will send personnel to supervise and aid in assessment and cleanup. You might want to consider distributing a short emergency response guide within your own organization to mine superintendents, maintenance supervisors, electrical foreman, etc. A suggested outline is included in appendix A. Other Information Emergency response: U.S. Coast Guard National Response Center, telephone 800-424-8802 (toll-free). Supplementary information on cleanup procedures and Federal requirements: U.S. Environmental Protection Agency, Control Action Division, Washington, D.C., telephone 202-755-8033. Information on foam plastic and concrete emergency dikes is available in the following publication: U.S. Environmental Protection Agency. Control of Hazardous Chemical Spills by Physical Barriers. Rept. EPA R2-73-185, 1973; available from National Technical Information Service, Springfield, Va., PB 221 493 030A. Information on protective clothing availability is available in the fol- lowing publication: U.S. Coast Guard. A Survey of Personnel Protective Equipment and Respira- tory Apparatus for Use by Coast Guard Personnel in Response to Discharges of Hazardous Chemicals. Available from National Technical Information Ser- vice, Springfield, Va., ADA 010 110. Other Regulations PCB spills into water are also regulated under the Clean Water Act. Rules proposed by the EPA under this act in the February 16, 1979, Federal Register list 299 regulated hazardous materials, including PCB's. Under these rules, any spill of PCB's in excess of 10 lb constitutes a "discharge" if the spill threatens to reach "the waters of the United States." Waters of the United States do not, at this time, include ground waters, so spills of PCB's in dry areas such as in some Western States do not constitute discharges as far as the Clean Water Act is concerned unless there is a chance the dis- charged fluid can find its way to a stream, river, swamp, or other body of 11 surface water. The proposed regulations require that any discharge of more than 10 lb of PCB's into water must be reported within 24 hours to the U.S. Government in accordance with procedures specified by the Department of Trans- portation in 33 CFR 153.203. (The proposed regulations also specify separate fines for spills of PCB's into the water.) Decontamination (40 CFR 761.43) The EPA regulations authorize decontamination of containers, such as steel drums that have been in contact with PCB's by triple rinsing with clean solvent. The volume of solvent used for each rinse must be at least 10 per- cent of the volume of the container. Movable equipment used in storage areas may be decontaminated by swabbing surfaces that have been in contact with PCB's with a suitable solvent. This same procedure could probably be used to decontaminate other machinery such as drag lines contaminated with PCB's. The preferred solvents for cleaning up PCB's are kerosene and light fuel oil. The workers should be issued protective gloves and other necessary pro- tective clothing as may be required by the conditions. Protective breathing apparatus may be necessary in some instances. Used solvents and other contam- inated materials must be stored in containers that have been marked. This contaminated material must be stored and disposed of in approved facilities. Contaminated gloves and other protective clothing should be discarded into the drums with the other PCB-contaminated solid material. Any PCB's that get onto workers' skin should be removed using waterless hand cleaner and paper towels, the paper towels then being disposed of as required for PCB's. Transportation [40 CFR 761.42, 761.20(b)] PCB's are not considered a hazardous material under the regulations of the U.S. Department of Transportation (DOT). Therefore, no special type of vehicle or placarding is required. However, EPA is planning to promulgate a comprehensive manifesting system for hazardous chemicals under the authority of the Resource Conservation and Recovery Act. PCB's will be covered under these requirements. Containers used to hold PCB's and contaminated material must meet the requirements specified by the EPA. Vehicles used to transport PCB's (includ- ing common carrier trucks and railroad cars) are required to have a PCB label applied to the outside of the vehicle if they are carrying PCB containers that contain (1) more than 45 kg (99.4 lb) of liquid having more than 50 ppm on PCB's or (2) one or more PCB transformers. It is not required that askarel transformers be drained before thay are transported. However, the cooling fins on transformers are fragile, and most of the PCB spills that have resulted in major expensive cleanup efforts have been caused by damage to askarel transformers during transportation. If an askarel transformer is drained before it is moved, there will be a greater 12 chance of damaging the coils; on the other hand, the cost of cleaning up a spill from a transformer after a truck accident or a loading mishap can be extremely high. Disposal (40 CFR 761.10) Special disposal requirements apply to all PCB equipment and to all mate- rials contaminated with more than 50 ppm PCB's except for small capacitors that contain less than 3 lb of PCB's. These small capacitors may be disposed of in municipal landfills in which the organic wastes are expected to adsorb and immobilize the PCB's after the capacitor casing rusts through. Solid spill materials contaminated with more than 50 ppm PCB's must be disposed of in an approved PCB landfill or special PCB incinerator. Disposal requirements for PCB equipment follow. You cannot contract away your responsibility for proper disposal of PCB's. If there is ever a problem and PCB's are traced to you, it is still your responsibility. The EPA regulations establish special and stringent requirements for chemical waste landfills and incinerators used to dispose of PCB's. To obtain a list of approved facilities, call (toll-free, 800-424-9065, or in Washington, D.C., local 554-1404) or write the Office of Industry Assistance, Office of Toxic Substances TS-799, U.S. Environmental Protection Agency, 401 M St., S.W., Washington, D.C. 20460. Contact the dis- posal facility for prices and special instructions before sending PCB's. EPA has not yet approved any incinerators for commercial disposal of PCB's, so all materials required to be disposed of by incineration must be stored in accordance with the regulations until EPA approves an incinerator. ASKAREL TRANSFORMERS The term askarel is defined by the 1978 National Electrical Code as "a generic term for a group of nonflammable synthetic chlorinated hydrocarbons used as electrical insulating media. Askarels of various compositional types are used. Under arcing conditions the gases produced, while consisting pre- dominantly of noncombustible hydrogen chloride, can include varying amounts of combustible gases depending upon the askarel type." In fact, all of the types of askarel sold prior to 1979 contained 60 to 100 percent PCB's, the balance of the mixture usually being trichlorobenzene. The unique advantages of PCB- based askarel used as a coolant liquid in transformers have been its chemical inertness and nonf lammability . Approximately 2 percent of the pad-mounted transformers in use in the United States contain PCB-based askarel coolant liquid. Askarel transformers have been used where fires might endanger human life and property. PCB's have the advantage of nonf lammability , in contrast to mineral oil, the other major liquid coolant used in transformers. Gaseous coolants are also nonflammable, but gas-cooled (dry-type) transformers have certain disadvantages when com- pared with liquid-cooled transformers. Dry-type transformers are generally more expensive than the liquid-cooled units, and they usually have increased operating noise levels and a lower capacity to withstand temporary overheating 13 caused by surges of power in the electrical circuit. Alternative liquid cool- ants are available, but none has all the advantages of PCB's. Uses of Askarel Transformers in Mining The advantages of askarel transformers in mining are the same as in any application: Askarel fluids are nonflammable. Askarel transformers are, of course, no longer being produced, but the ones that are in service will be permitted to remain in service for their occupational lifetimes, which in many instances could be 30 to 40 years or maybe longer. As will be pointed out below, none of the alternatives to askarels are direct replacements for askarel-cooled transformers. Transformers cooled with gases, for instance, present very little fire hazard, but they are voltage limited because of the inherent characteristics of gases, and gases simply do not have the heat capacity of liquids. Liquid-cooled transformers are therefore better where transformers are likely to be occasionally run at a higher than design load- ing. The alternative "high-fire-point transformer liquids" are all more expensive than askarel and do not have the same fire resistance. Oil-cooled transformers, the mainstay of the transformer industry, are the least costly of all transformers available, but in applications requiring fire safety, they must be installed in fire-resistant vaults that can cost several times as much as the basic transformer. Askarel-f illed transformers are used in all phases of mining: Under- ground, in surface installations, and onboard large mobile surface machinery. Transformers used in mining range in size from 10 to 8,500 kva and contain up to 3,415 gal of askarel. Machine Mounted The major manufacturers of large surface mining equipment installed aska- rel transformers on a small portion of their equipment. This was generally done at the request of the company purchasing the machinery, though Page Engi- neering used askarel transformers on all of its walking draglines. Bucyrus-Erie used to provide askarel transformers on electrically powered draglines, loading shovels, and blast-hole drills. Usually the customer was being required by its insurance carrier to use a nonflammable transformer fluid. Askarel transformers, when requested, were mounted inside the machin- ery in steel rooms that had originally been designed for oil transformers. These rooms usually had an opening in the floor that would duct the trans- former fluid to the ground to reduce the fire hazard in the event of a trans- former rupture; the rooms also contained openings to provide adequate ventilation. These transformers were 100-to 250-kva single-phase units. It is estimated that askarel transformers were installed on 5 to 6 machines out of roughly 400 that were built by Bucyrus-Erie over the past 15 years. 7 Bucyrus-Erie quit suppling askarel transformers around the first part of 1977, and currently use only mineral oil transformers, but they are investigating the use of silicone filled units. 7 Telephone conversation with Dick Matusak, Bucyrus-Erie, August 5, 1977. 14 Marion Power Shovels also supplied askarel transformers in the 100-kva range on its shovels and draglines at customer request. Askarel-f illed trans- formers were mounted on only a small percentage of the 1,000 electrically powered machines that Marion has built. As in the case of Bucyrus-Erie, askarel-f illed transformers were mounted inside the machine in the fire- resistant rooms that had been designed to meet specifications for oil-filled transformers. Marion quit supplying askarel filled transformers during 1975. 8 In contrast with the preceding two companies, Page Engineering, supported by its insurance company, used askarel-f illed transformers on all the walking draglines it built before 1977. Each dragline contains a bank of three single-phase transformers in the 100- to 333-kva range. These transformers are mounted in cages on steel platforms about 8 ft above the main deck of the dragline. A major rupture of one of these transformers would result in PCB's leaking onto the ground underneath the dragline. An estimated 25 of these machines have been built over the past 10 years. In addition to the above equipment, an undetermined number of blast-hole drills built by Robbins Drill Division of Joy Manufacturing used three single- phase, askarel-f illed transformers. Equipment that uses askarel transformers is used by a relatively small number of mines. In some cases, the mining company was required by its insur- ance carrier to order askarel transformers; thus most or all of the equipment at these particular mines contains askarel transformers. In addition, it is not unusual for a company to order its large equipment from a single supplier. If the supplier were Page, all the draglines at that mine would have askarel transformers on board. Underground According to information obtained from Electric Service Co., a trans- former service company, from comments made during a telephone survey of load center manufacturers and from information obtained during the mine visits, there are few askarel-f illed transformers in use underground in coal mines. All load centers used dry type transformers that have been designed to with- stand the environment in the mines. When questioned about potential diffi- culties with dust or dampness in the mines, manufacturers replied that these conditions do not cause major problems. The few askarel transformers that are in use in underground coal mines are gradually being taken out and replaced with dry type transformers. The relative scarcity of askarel transformers in underground coal mines is not duplicated in underground metal/nonmetal mines, where the use of aska- rel transformers is widespread. During visits to three underground mines, askarel transformers were found in numerous locations in the underground dis- tribution system, covering all applications from main underground substations to small units on lighting circuits. The mountings for these transformers ranged from concrete pads level with a damp mine floor to diked, elevated a Telephone conversation with Joseph Ivy, Marion Power Shovels, August 8, 1977. ^Telephone conversation with Frank Oslakovic, Page Engineering Co., August 10, 1977. 15 concrete pads. At two of the mines visited, a major askarel leak would easily find its way into the mine water. This water was being pumped to the surface where it was being used in ore processing operations and was subsequently impounded. A major askarel leak in these cases could cause widespread contamination and would be extremely costly to clean up. Failure of an askarel transformer accompanied by an internal electrical arc can vaporize a considerable quantity of PCB's that will then be released through the pressure relief valve. The National Electrical Code requires that askarel transformers located in buildings be vented to the outside because of the potential health problems that could result from worker exposure to high concentrations of PCB vapors. No such venting is possible with those askarel transformers used underground, the mines presumably accepting the increased risk of toxicity as a tradeoff for reduced f lammability. The extent of askarel transformer use varies from mine to mine. At one mine only the main underground substations used askarel transformers, and the remaining transformers were either oil filled or dry type. At a second mine all the underground transformers were askarel filled as a matter of company policy. Surface The use of askarel transformers at the surface facilities of underground mines, both coal and metal /no nmetal, and at the ore processing facilities at strip mines, is also common. Askarel transformers are used any place where such use is required by the National Electrical Code, generally any indoor location where the transformer is not mounted in a fire-resistant enclosure. The transformers that were observed ranged in size from 50 kva single-phase units, which contained roughly 40 gal of askarel and fed an auxiliary power circuit, to 8,500 kva three-phase units that contained 3,415 gal of askarel and served an electrolytic zinc plant. The only environmental problem associated with the present siting of these transformers is that in most cases a major askarel lead would almost certainly find its way through numerous floor drains into the water system of the surface facility. Number of Askarel Transformers Used in U.S. Mines The information in tables 2 and 3 refers specifically to askarel transformers. Although reference will be made to both askarel transformers and to PCB transformers, the terms are not synonymous. "Askarel transformers" contain askarel, while "PCB transformers" includes askarel transformers plus any other type of transformer that for whatever reason (usually inadvertent contamination) contains more than 500 ppm (0.05 percent) PCB's. This distinction and the problems it imposes are discussed in greater detail later in this publication. The 2 percent of all transformers cooled with askarels amounts to between 135,000 and 140,000 transformers nationwide. The estimate of the number of askarel transformers in service in mines was based on data gathered in 20 mine 16 visits. Table 2 summarized the results of visits in terms of stationary transformers, machine-mounted transformers, and surface and underground transformers. TABLE 2. - Summary of askarel transformer data gathered during visits to mines ~~-\ Production, million tons ore per year Number of askarel transformers Mines Machine mounted 1 Total Surface metal/nonmetal: 1 2.8 31.4 20.0 7.7 10.2 3.3 NA 1.6 NA 8.1 3.2 1.7 1.6 New 4.0 1.9 6 15 NA NA 12 ( 2 ) 1 6 2 44 3 Surface coal: 1 65 15 2 1 3 Underground metal/nonmetal: 1 NA 24 2 25 3 Underground coal. NA 3 6 12 2 1 NA Not available. Underground transformers for all underground mines. -Nearly all. %o data available fr om mines 5-11. Overall estimates of the number of askarel transformers in use by the various portions of the mining industry have been based on these data and other information obtained over the period of this study. These numbers are shown in table 3. 'For the coal industry, the estimates were made by directly extrapolating the number of transformers at the mines surveyed, based on the tonnage produced at those mines compared with the tonnage produced by the entire industry. For the metal/nonmetal industry, the extrapolation was done based on a comparison of the electrical consumption of the entire industry. The estimate of the number of transformers includes all mining, crushing, grinding, washing, drying, and benef iciation operations for each segment of the mining industry. It is likely that these estimates constitute an upper bound on the number of askarel transformers actually in service because visits were made to those mines known to be using askarel transformers. 17 TABLE 3. - Extrapolated estimates of numbers of askarel transformers in various mining segments Industry segment Number of askarel transformers 1,600 1,300 400 100 Total 3,400 How To Identify an Askarel-Filled Transformer The following methods can be used to determine whether or not a transformer is cooled by askarel (PCB): (a) Nameplate data — Most transformers will have intact nameplates con- taining details on the size of the unit and the weight and volume (usually in pounds and gallons) of the coolant. In almost all cases where askarel cool- ants are used, the nameplate will contain the manufacturer's trade name for askarel. The following trade names for transformer askarel are the ones most likely to be encountered: Manufacturers * Trade Name Allis-Chalmers Chlorextol American Corp Asbestol Electro Engineering Works NA Envirotech Buell NA ESCO Manufacturing Co Askarel 2 Ferranti-Packard Ltd Askarel 2 General Electric Co Pyranol H. K. Porter NA Helena Corp NA Hevi-Duty Electric Askarel 2 ITE Circuit Breaker Co Nonflammable liquid Kuhlman Electric Saf-T-Kuhl Maloney Electric NA Niagara Transformer Corp Askarel 2 EEC-18 Power Zone Transformer EEC-18 R. C. Uptegraff NA Research-Cottrell Askarel 2 Standard Transformer Corp NA Van Tran Electric NA Wagner Electric No-Flamol Westinghouse Inerteen ? Nepolin ? Dykanol NA Not available. ^This list is not necessarily complete. PCB's have been used since 1929, and many companies have gone out of business. ^Generic name used for nonflammable insulating liquids in trans- formers and capacitors. (b) If the nameplate does not show one of the above tradenames for aska- rel and if it is not plainly written on the nameplate that the unit is oil cooled, then a determination can be made on the basis of the fluid density by dividing the weight of the cooling fluid by the number of gallons. Fluids weighing less than 8 lb/gal are definitely askarel. Fluids of intermediate density should be chemically tested unless the manufacturer of the unit can identify thev coolant. (c) If no nameplate data are available (sometimes nameplates become lost or obscured over the years and cannot be read), then a sample of fluid should be withdrawn and tested to establish its density. A simple test consists of using a small amount of water into which a single drop of the fluid 'in ques- tion can be dropped. The amount of water needed should be kept very small because if the fluid does turn out to be askarel, the test water will have to be disposed of in the approved manner. The test is this: If the drop of fluid sinks in the water, it is askarel; if it doesn't, it isn't. (d) In many instances where transformers are listed as containing oil, they may in fact contain small, but significant, amounts of PCB. This small content of PCB is the result of the past common practice of topping off oil- filled transformers (after samples have been withdrawn for testing of electri- cal properties) with spare askarel fluid instead of with transformer oil (mineral oil). There is no easy way to test such PCB-contaminated oil; a small sample must be extracted and properly packed and sent to a testing labo- ratory equipped to measure the PCB content of the fluid. If the oil is found to contain more than 500 ppm PCB, the transformer will have to be treated as if it is an askarel transformer in order to be in full compliance with Federal regulations. Oil-filled transformers may be assumed to be "PCB-contaminated trans- formers" unless it is known that the oil contains more than 500 ppm PCB's. EPA Requirements for PCB (Askarel) Transformers Definition : PCB transformers are those liquid-filled transformers in which the liquid contains more than 500 ppm PCB's. (Note: PCB transformers mounted on railroad locomotives and multiple-unit electric commuter cars are covered by different requirements.) Manufacture, import, and sale of new PCB transformers : Banned Use : Continued use of nonleaking PCB transformers is authorized indefinitely. Diking : Not required, but you are responsible for cleaning up all spilled PCB's. Marking : A large (6-inch-square) label must be applied to each PCB aska- rel transformer. 19 Recordkeeping : The central PCB records must contain the identity and location of each PCB askarel transformer; the weight of PCB's contained in each unit; the date each transformer is removed from service, placed into storage, and shipped for disposal; the storage location and disposal location for each transformer removed from service; and the name and address of the purchaser of each PCB transformer that is resold. Resale of used nonleaking PCB transformers by user : Authorized. Servicing : Authorized provided the coils are not removed and there is no change in ownership of any PCB's. 10 Rebuilding : Banned (coils may not be removed from the tank). Retrof illing (substitution of other liquid for PCB's): Authorized if there is no change of ownership of PCB's. 11 The transformer must still be considered a PCB transformer as long as the concentration of PCB's in the liquid is above 500 ppm by weight (1 lb PCB's in 2,000 lb of liquid). A retrofilled transformer may no longer meet the definition of an askarel trans- former established by the National Electrical Code and may therefore have dif- ferent code restrictions on its use. Processing of used PCB askarel for reuse : Authorized provided there is no change in ownership of the liquid. 12 Sale of new or reclaimed PCB askarel: Banned. 13 Storage of new or reclaimed askarel : Must be in special storage areas meeting the EPA requirements. Disposal : Drain liquid PCB askarel into approved containers. Fill transformer with kerosene or fuel oil, allow to stand for at least 18 hours, and drain into approved containers. Seal up drained transformer and dispose of in an approved chemical waste landfill. Dispose of liquids in an approved chemical waste incinerator (at present, store until an approved incinerator becomes available). Storage beyond 30 days to be in special area. Scrap recovery of failed PCB transformers : Banned. Spill cleanup : All material contaminated with more than 50 ppm PCB's must be picked up and disposed of in facilities approved by the EPA. 10 Unless the seller of PCB's has applied to the EPA for an exemption from the ban on "distribution in commerce" of PCB's and EPA has granted the exemption. Change of ownership for purposes of approval disposal is allowed. ^See footnote 10. 12 See footnote 10. 13 See footnote 10. 20 Precautions for Continued Use As pointed out above, there are about 3,400 PCB askarel transformers presently in use in the U.S. mining industry. The EPA regulations will allow these transformers to remain in service until they fail, provided the special PCB label is applied to each unit and the required records are kept. However, the EPA regulations require special disposal of any material that is contami- nated by PCB's spilled or vented from any transformer, whether caused by acci- dental damage to the transformer or by electrical failure of the unit. The resulting cleanup costs can be very high if large quantities of soil are con- taminated or, particularly, if PCB's enter any sewer, stream, or other water. In addition to the costs incurred in cleaning up spilled PCB's, the owner of a failed transformer may be subject to stiff fines for improper disposal of PCB's if it is not possible to recover all the lost fluid. The risk of large, uncontrolled PCB spills can be minimized by analyzing the possible risks associated with each PCB askarel transformer and by taking steps to contain the uncontrolled spread and loss of PCB's from the unit. This section describes a number of methods that can be used to secure trans- formers against spills, including: Dikes Berms Curbs Plugging of water drains Transformer retrofilling Transformer relocation Fences and vehicle barriers Emergency foam packs Special problem transformers Significance of Water When PCB's leak into the environment from transformers or from any source, the already widespread PCB pollution problem becomes aggravated. Recovery or cleanup of spilled PCB's is usually expensive, partly because the disposal costs are high and partly because special effort must sometimes be expended, as in cases where PCB's spill into water. When PCB's spill onto land (that is, onto soil or dirt) the cleanup pro- cedure consists primarily of removing the contaminated soil and disposing of it in an EPA-approved chemical waste landfill. This can be expensive. The amount of soil that has been removed following spills has been tens of thou- sands of barrels, which after transport and burial costs, can easily run to costs of more than $100,000. Spills into water, however, are vastly more complex and therefore more expensive. Even spills into nonf lowing lakes or swamps, as opposed to rivers or streams, result in extreme cleanup costs because of the dredging operations that are invariably necessary and because of the greater volume of waste mate- rial (for example, earth and sediment) that must be handled, packaged, shipped, and buried. In rivers where the moving water can both aggravate the 21 cleanup operation as well as spread the PCB's that are stirred up from the bottom sediments during the dredging operations, cleanup costs can be high and, at the same time, substantial environmental pollution can still result. In one instance in Washington State, an askarel transformer containing about 250 gal of fluid was accidentally dropped on a dock and leaked into a river. After all the cleanup operations, it was calculated that only about 7 percent of the askarel was recovered, and the cost was close to half a million dollars. Cleanup of spills that occur on land can be especially costly if the spill threatens to contaminate groundwater that is used for drinking. Vast amounts of soil may have to be removed to approved chemical waste landfill facilities, and costly tests must be performed to insure that the contamina- tion has been contained. Thus the presence of water near a leaking transformer is an important consideration in deciding how to best manage a PCB askarel transformer. Decision Guide In general, the objective in the securing of PCB transformers is to insure that any large leak of fluid will be contained within a specified area away from access to water of any kind (including sewage water and drainage systems that connect to either sewage systems or to any type of water body including groundwater). It is expected that in most instances (at least 3 out of 4 times) it will be feasible to either build a dike around the transformer and switch gear assembly or to effectively dike the entrance ways to the shel- ter or rooms that contain the units. In all instances, the inspector or engineer who makes the decision on how to deal best with a given transformer should be on the lookout for all possi- ble methods by which fluid can escape into the environment. For outdoor transformers, sheltered or unsheltered, the proximity of soil and access to water by way of floor drains, ditches, or whatever method, should be noticed and taken into consideration in establishing both the priority and the type of confinement for a given transformer. For indoor and underground transformers, drains should be pinpointed and should be plugged and sealed. Otherwise, efforts should be taken to insure that spilled fluid will be restricted from access to the water. For all transformers, spill confinement measures should include assurance that transformer mounting pads are not cracked or broken, that adjacent walls that may become part of proposed spill-confinement system (especially walls made of porous materials such as cinderblock) are well sealed near the floor, that the interface between the walls and floor (this is called the wall-floor interface) is sealed, that there are no holes in the floor such as conduit access holes through which fluid can drain, and that there are sufficient bar- riers and/or fences to protect the unit from damage from vehicles (automobiles and lift-type trucks) and from damage by people who may be moving or working in the area. 22 It is not felt that it will be necessary to use the following decision guide in order to effectively analyze all transformer settings for spill potential and optimum spill confinement measures. It is likely that whoever uses this guide will, by doing so, quickly learn to see the points that need to be considered without having to refer to the guide. Decision Guide Questions and Considerations 1. If the PCB askarel is located on the surface inside a building or outside, is there any way that fluid leaked from the unit could find its way to either a water drain (such as a sewer or a gutter leading to a sewer) or directly to water (for instance, by running downhill and into a stream or swamp or river)? If so, such units should be given priority in spill prevention mea- sures. If not, the unit should still be secured against leaks, though the urgency is not as great as that of units located with access to water. 2. If the transformer is located below ground, or even simply below grade, in a location from which groundwater must be continually pumped, is there any way that fluid leaked from the unit could find its way into the water? Since groundwater is usually pumped out of mines, PCB contamination could easily be spread to larger volumes of water and soil, and if the water is used in ore processing, it could also contaminate the ore and processing plant. Transformers in such situations should be given priority in spill pre- vention measures. 3. In some instances PCB transformers are located in rooms or in alcoves that appear to be secure against the loss of fluids to either water or soil; if this is the case, are there curbs or diking either around the transformers or across the entrance ways to the transformer rooms so that the units are completely secure against uncontrolled loss of fluid? 4. In cases where transformers are situated in rooms with porous cinder- block walls, are those walls sealed with either grout type sealers or with a heavy type of paint that is not soluble in chlorinated hydrocarbon solvents such as PCB and trichlorobenzene? 5. If the transformer is otherwise secured against leaks, is the mount- ing pad or the floor of the transformer room free of cracks? Cracks that look like they would not prevent the loss of fluid should be grouted and painted with solvent resistant paint that will serve the dual purpose of sealing smaller cracks not grouted and of sealing the pad against water absorption that in cold places can cause freeze fracturing of the concrete. 6. Is the transformer in a location where vehicular traffic might be a hazard? For instance, is it located near to a driveway or next to a parking lot? If so, a vehicle barrier might be useful, expecially if the unit is located where a body of water might be threatened by a loss of fluid. 23 7. Is the transformer located near machinery that might throw projec- tiles with sufficient energy to damage the unit? Is the transformer located in a place where forklift vehicles might accidently run into it or snag the heat exchanger or some other part? If so, fences or vehicle barriers might be necessary to provide protection, unless it is reasonably feasible to either relocate the transformer to a safer place or to replace it with a non-PCB transformer. 8. Is the unit mounted on unwelded steel plates (as might be the case if the unit is platform mounted), mounted on a second story, mounted in a mobile machine, or mounted on some other type of surface that might be extremely difficult to seal against fluid loss? Such a unit could be tempo- rarily removed while the mounting surface is sealed. If the transformer does not present an immediated threat to water or to personnel and would not pose any great difficulties in a cleanup should a spill occur, then no securing measures need be taken. 9. If the unit is pad mounted, is there room for installation of a dike on the edge of the mounting pad? If not, and if some kind of spill protection is needed, either the pad could be extended and a curb installed as part of the extension or a berm of asphalt, concrete, or clay could be built around the unit. 10. If the unit is mounted near a wall that will be part of the spill containment barrier, is the wall of nonporous material such as concrete or sealed cinderblock and is the wall-floor interface tight against fluid loss? 11. If the transformer is in a special room, alcove, or vault, is this area used as storage space, for example, for brooms and other building mainte- nance materials? If so, and if there is no other better storage place for the stored materials, it might be best to put a dike around the transformer itself rather than to secure the room as a whole to prevent additional cleanup expense from contaminating extra material. 12. If the transformer is in a special room, alcove, or vault, are there also drains in the room that cannot be sealed and removed from service because they are needed to remove water from other systems sharing the room with the transformer (for example, an air-conditioning system)? If so, the transformer rather than the whole room will have to be diked against the possibility of a fluid leak. 13. If the room is used for nontransformer-related activities, is the unit sufficiently protected against the potential for mechanical damage? 14. If the unit is located outside and is already adequately diked against the possibility of fluid loss, is there an allowance for the removal of rainwater by a properly designed water-only drainage system? The design of a water-only drainage system that can be built from exiting plumbing hardware is included as appendix B of this report. 24 15. Is the unit old or does it appear to be old? If so, this may be a consideration in whether or not to replace the unit. There are commercial transformer service companies that are experienced in the testing of trans- formers to find out whether or not they are in condition to continue in service. 16. Is^there any evidence of an active leak from the transformer? If so, and if it is due to corrosion or a broken or cracked weldment, the unit should probably be replaced. Otherwise, arrangements should be made to repair the unit, especially if it is located near water or a path to water and if there are no immediate plans to secure the unit against fluid loss. (NOTE: Approximately 10 percent of pad-mounted askarel transformers show some evi- dence of leaking.) If the unit has to be replaced, is its setting suitable for the installation of an oil-filled transformer? That is, does the setting satisfy the NEC requirements for the installation of oil-filled transformers (indoor or outdoor)? If not, the new transformer will either have to be of a fire-safe design, or an oil-filled transformer will have to be installed in a different location. Dikes A dike is the most effective, aesthetically appealing technique for con- taining a potential spill. It is also among the least costly of spill preven- tion measures, expecially when compared with the alternatives of retrofilling and relocation discussed below. A suggested steel dike system shown in figures 2 through 5 consists of steel angles (measuring 3.5 by 6 inches) that are bolted to the periphery of the mounting pad. The seal between the dike and the pad consists of a gasket of 3/8-inch-thick closed cell neoprene foam rubber. The corners of the dike are bolted together by means of 2- by 2-inch steel angles. Concrete pad 6-inch-high angle steel with 3.5 foot base and 5/16-inch wall thickness Corner joint of 2- by 2- by 1/4-inch angle steel FIGURE 2. Typical transformer and switch gear on con- crete mounting pad with steel dike installed. An alternative to this steel dike system is a con- crete, curb-type dike. How- ever, the concrete dike may be more costly to install and, since it would have to be at least 5 inches wide to be sufficiently durable, would require more room on the periphery of a trans- former pad than the steel dike. In cases where the mounting pad is small, this can be an important consid- eration. Also, the curb- type dike would slightly inhibit the accessibility of the transformer for mainte- nance operation, moreso than the steel dike. 25 3 Co c o <D O CNI >~ . -Q C . £ ON O .1 s o © 1 i o c o tu ZD O u_ "O * CJ a o ;= to 5 +i "Ik *• 2 a •>- £ -a Z S 5 g 5 £ 1 1 00 *+« oo 0) C 0) JS 1 ? 0) ^ u o = E „ T5 E a 0) in « ■- o) c » 75 t S S r 5 0) <- ♦• in P c-R c o 10 X n £ n * » 2 J 4) 0) ; = *■ is .£ <0 «- "O CM E -2 2 CTl ~ a u c c c o CO c a U SO CO. o .E c "5 ' o _3 '^ u o c o Q. <D 0) cn §■ s c o LU o 26 N 5> •- c c CO 5- S.I £ a V .E a) J£ 1 +j & o f s I 3 it) Q. O • 0) 05 O CQ .2 u GJ c o > LU O 27 Dikes can be installed in both indoor and outdoor locations. In outdoor locations, however, especially in parts of the country where rainfall is excessive, provision must be made for water drainage in order to minimize the corrosion hazard to the transformer-related switch gear and casings. A water- only drainage valve, along with the parts specifications, is shown in fig- ure 6. It will permit the passage of 3 gal/hr of water (when submerged 3 inches deep), but will close if the level of askarel approaches the level of the drain opening. Clean this surface and coat with epoxy joining compound immediately before pouring cement 3/4" to 1" re-bar (A) Soil t 6" 1 i L _ Q _ 0_ _ Mounting pad _) Pad extension as cast FIGURE 7. - Schematic diagram of basic parts and dimen- sions of an extended mounting pad: A, exca- vation and re-bar location; B, cross section of extended pad. Curb-type dikes can most easily be installed in those instances where the mounting must be enlarged because of insufficient room even for the steel dike. Figure 7 shows the typical requirements for the enlargements of a mounting and the installation of a curb dike. Berms A berm is simply a mound of earth or asphalt surrounding an outdoor transformer. A berm, espe- cially an earthen one, would take up much more room than a steel dike, and if porous enough to allow the drainage of rainwater, would also be too porous to give maximum protection against high cleanup costs in the event of a PCB spill. On the other hand, it would be dif- ficult to install an effec- tive water-only drainage system in a berm if the berm were adequately waterproofed with a lining of bentonite or some other impermeable clay. Asphalt berms con- structed on asphalt or con- crete surfaces that surround a given transformer mounting 28 might be a low-cost alternative to dikes, but they can restrict accessibility of the transformer and are not as aesthetically appealing as a dike. In cases where there is a moderate problem of water accessibility to a potentially leaking transformer, and where the transformer is in a location where vehicular damage is a possibility, such as near a parking lot or street or driveway, a berra could provide both security against leaks and protection from vehicles. Fences and Vehicle Barriers It is probable that a small number of PCB transformers will be found in locations where the threat of damage from moving vehicles should. be taken into consideration (for instance, in locations where forklift type vehicles are commonly used, either indoors or outdoors, and next to parking lots and close to driveways). In some cases, chain-link fences will provide adequate protection against lightweight freight vehicles, but usually where vehicle damage to transformers is possible, heavier protection such as that depicted schematically in fig- ure 8 is advisable. The simple pipe-type barriers can be installed with 1.5 feet if surrounded by concrete or asphalt pavement 5-inch-diameter steel pipe, 1/4-inch wall, concrete filled FIGURE 8. 3 feet if set in concrete but surrounded by sod Vehicle barrier suitable for protection of an askarel transformer located in a park- ing lot or next to a street. 29 relatively little effort and cost, and in many instances, one pipe of suffi- cient diameter will provide adequate protection. Curbs and Doorway Dikes Transformers, PCB or otherwise, are often mounted in special transformer rooms. Whether the room is inside a larger building or is a free-standing structure, the least costly method of securing the transformers against PCB loss is often to install a dike or concrete curb at entrances. The only cases where an entrance sill may not provide adequate protection would be where there is a drain in the room with the transformer that cannot be plugged (say, because the room is shared with an air-conditioning unit that must be provided a drain for the runoff of condensation), or where the floor or walls will not provide a tight sealing barrier against fluids. Walls of special enclosures are often made of unpainted cinderblock built onto concrete mounting pads. In this case, both the walls and the interface between the wall and floor must be sealed with a material that is only minimally soluble in chlorinated hydrocar- bons (PCB's and triclorobenzene). This can be done by grouting with cement or other inorganic material and then painting. Emergency Foam Packs Possibly the most cost effective means of spill control — but not of prevention — is with the use of emergency foam packs. These are back-mounted units capable of dispensing up to 70 cu ft of urethane foam that can be used to form a fluid barrier very rapidly. However, there are certain disadvan- tages to these units, including the need to keep at least one person in train- ing and on call in the event of a spill. Also, the urethane foam will not adhere well to wet surfaces nor will it provide a good fluid barrier if located on porous or sandy soil. On concrete or asphalt, urethane should make an effective instant dike. The problems with wet surfaces have been studied, and some solutions have been found. For additional information the interested reader is referred to the following publication: U.S. Environmental Protection Agency. Control of Chemical Spill by Physical Barriers. Pub. EPA-R2-73-185, March 1973; available from National Techni- cal Information Service, Springfield, Va., PB 221 493 OBA. Special Problems Instances will probably arise where no set of preestablished procedures will apply to a special-problem transformer. For instance, sometimes in order to conserve floor space, indoor-mounted transformers are mounted on raised platforms 10 or 12 ft or more above the floor, often on a platform of steel plates that are not welded together to form a liquid-tight seal. This is com- mon in draglines. In such a case, there is no way to dike and to seal the platform against fluid loss without temporarily raising the transformer and then welding the platform plates together. But the effort in temporary removal of an askarel transformer is not much less than the work required to relocate the unit either on the floor (on concrete, diked) or outside the 30 building. A similar effort could replace the unit with a different fire-safe transformer or with an oil-filled transformer mounted outside. In other words, the amount of effort to secure a transformer against fluid loss to adjacent work areas and to the environment at large might be more than is jus- tified by the probability of a major leak. It might be more effective in the long run, if water or vast amounts of porous soil are not threatened by a pos- sible leak, to leave the PCB unit in service without precautions; if water is a problem, it "might be best to replace the unit rather than to secure it against leaks. Most transformers can be readily secured against fluid loss, but protec- tion of those that are resistant to easy solution will have to be decided by comparing cost of securing the unit against fluid loss or removing it to a better location versus the potentially high cleanup costs should a leak occur. Mobile Mining Machinery Transformers are used on electrically powered draglines, shovels, and blasthole drills to reduce the incoming high voltage to the levels required by the drive motors. In most instances, mobile mining machines have been designed to safely use oil-filled transformers. However, several mining com- panies have asked that machines be delivered with askarel transformers, and the manufacturers have complied. There appears to be no general method for securing onboard askarel trans- formers against loss of fluid. In some instances there is sufficient room to allow the installation of transformer dikes; in some cases, however, the sim- ple installation of a dike would not be sufficient; for instance, the mounting surfaces often consist of a floor made of steel plates that are butted up against each other without being welded or sealed. Welding of mounting sur- faces under transformers would require the temporary removal of the trans- former, an undertaking that would be almost as costly and time consuming as replacement of the units with nonaskarel units. Most mobile mining machinery that contains PCB transformers is used in surface applications. The loss of PCB fluid from an onboard transformer might be difficult to clean up if it runs into the complex portions of the machinery, but the loss of fluid to the ground would probably be unaggravated by the presence of water in most instances. The cleanup procedure would con- sist of decontaminating the machine and the containers and of disposal of earth and soil. If anything general can be said about the precautions that can be taken with respect to askarel transformers on mining machines, it is that the indi- vidual mining companies will probably have to use some subjective measures to determine whether the cost of securing their mobile-mounted askarel trans- formers against leaks is likely to be less than the cost of fines, penalties, and cleanup costs in the event of a transformer failure. 31 Relocation of Transformers It has been noted in many transformer surveys, at mines as well as in other industries and operations, that not all askarel transformers are located in places where electrical codes or safety considerations require their use. In such cases, especially where a fluid loss from an askarel or PCB trans- former could reach water or otherwise cause local or environmental damage, the simplest and securest solution is to replace the PCB transformer with an oil- filled unit and to relocate the original transformer in a site known to be secure from leaks. It might be feasible in a small number of cases to simply exchange two transformers, location for locations, and to totally eliminate any other PCB securing measure. Retrof illing Retrofilling is the replacement of the PCB askarel fluid in a transformer with non-PCB fluid. Askarel transformers located in places where fire hazard is a consideration can be retrofilled with silicone fluid or with the new high-fire-point hydrocarbon fluids that are available. However, retrofilling is expensive and a single retrofill does not usually reduce the concentration of PCB's to below 500 ppm. Typical commercial costs for field retrofilling of askarel transformers are $30 per gal of capacity of the transformer, and this does not include the cost for storage of the PCB fluid removed or of the solvent fluids used to flush the transformer at the time of retrofill. (PCB storage is necessary until approved PCB incineration facilities become available; cost of disposal is expected to be high because it must include the cost of shipment by an approved method; the actual cost of incineration will probably be on the order of several dollars per gallon of PCB's.) Retrofilled transformers must be marked and handled as PCB transformers unless the concentration of PCB's has been reduced to below 500 ppm. A transformer must be retrof illled a^t least 3 times to get the concentration of PCB's to less than 500 ppm. Successive retrofills should be at least 18 months apart. The major advantage of retrofilling is achieved only if the concentration of PCB's is reduced to below 500 ppm by repeated replacement of the liquid. Once the concentration of PCB's has been reduced to this level, the trans- former may be considered a PCB-contaminated transformer and may therefore be rebuilt if it fails. If a PCB askarel transformer is in a critical applica- tion and the time saving achieved by rebuilding rather than replacing the unit when it fails offsets the cost of multiple retrofilling, this procedure might be justified. However, once the unit is filled with oil, silicone, or high- fire-point transformer liquid, the risk of fire is increased, and although the total amount of PCB-filled units in the unit is decreased, the same cleanup requirements exist as for PCB-filled units if the concentration of PCB's is above 50 ppm. The technology for reducing residual PCB levels in retrofilled trans- formers is rapidly being developed, and the supplier of the liquid should be 32 contacted to determine the cost and feasibility of achieving the 50 ppm level of PCB's in retrofilled transformers. The companies most active in this field are — For Hydrocarbon fluids: RTE Corp. Fluids Division 1900 East North St. Waukesha, Wis. 53186 414-547-1251 For silicone fluids: Dow Corning Corp. Midland, Mich. 48640 517-496-4000 Non-PCB Replacement Transformers New PCB askarel transformers have not been manufactured in the United States since 1978, and EPA regulations prohibit the manufacture of additional new PCB units or the rebuilding of existing units. Therefore, it will be necessary to replace every existing PCB askarel transformer, either when it fails or because there is too great a risk of uncontrolled PCB spills and no adequate way to dike or protect the transformer. There are a number of alternatives to the use of PCB askarel trans- formers, but each type is characterized by different tradeoffs of fire safety, overload capacity, and initial price. Most existing large non-PCB trans- formers are filled with transformer oil, which is a refined petroleum oil with viscosity and flammability characteristics comparable to those of SAE 10 motor oil. Oil-cooled transformers are the least costly units available for instal- lations where the potential fire hazard presented by the oil is not a problem. Askarel-f illed transformers have almost all the advantages of oil-cooled transformers, plus they are the most fire safe of any kind of liquid-filled transformer. (The disadvantages of askarel compared with oil, aside from the obvious ones of the recently recognized toxic and environmental hazard, are such minor considerations as the higher solvency strength of askarel on the insulation components of transformer windings, plus slightly lower dielectric strength than oil, and a tendency for the askarel to form corrosive HC1 under conditions of internal arcing or even during corona discharge; the latter effect results in a more stringent maintenance program for askarel trans- formers than for oil transformers.) The alternatives to askarel transformers are listed, described, and com- pared below. No one of the alternatives has all of the advantages of askarel transformers, all cost slightly to significantly more than askarel trans- formers, but none present the environmental hazard with PCB's. Some alternatives have special advantages possessed by neither oil nor askarel transformers. The attributes of the different types of non-PCB alternatives are given below; they are compared on an installed cost basis, and a simple decision guide is supplied at the end of this section. 33 Characteristics of Non-PCB Replacement Transformers Oil-Filled Transformers The major disadvantage to mineral oil is its f lammability. Transformer mineral oil has a flash point of 145° C, and if an arc occurs within the transformer, the breakdown products will be hydrogen and methane, which are also flammable. Detailed records of such failures are maintained by the electrical industry. Fire underwriters do not approve of the use of oils and other flammable liquids for indoor applications; where oil-filled transformers are not specifically prohibited as onsite replacements for askarel-f illed units, the National Electrical Code imposes certain restrictions upon their mode of installation. If safety were not a consideration, there would be no reason why oil-filled transformers could not be used in all applications. Askarel-f illed transformers cost about 1.3 times as much as oil-filled units of the same capacity, and thus most users prefer the oil type where possible. The oil-filled transformers are the same size as the askarel units, and they are considerably lighter in weight. In addition, mineral oil has somewhat better heat-transfer characteristics than does askarel, and an electrical arc in mineral oil results in breakdown products that are noncorrosive. Oil-filled transformers can be used in these applications only if they are suitably isolated from flammable structures or if these structures are suitably safeguarded against fires. Where transformers are located outside the building or mine they service, however, the low-voltage power must be brought into the building via cables or insulated buses, incurring additional energy losses due to Joule heating in the additional low-voltage transmission lines. The National Electrical Code specifies the vault requirements for oil-filled transformers in indoor locations. Building a fire-resistant vault can double the installed cost of the transformer. There are apparently no Federal regulations that prohibit the use of oil- filled transformers in underground mines. Although some mines have removed all oil-filled transformers from underground installations because of the fire hazard associated with the possible loss of hundreds of gallons of hot oil, other mines have used oil-filled units underground for years with no problems. Adequate safety underground can be achieved by installing an oil-filled trans- former in a vault that is equipped with automatic dampers on the ventilation openings and automatic fire supression systems that would flood the vault with carbon dioxide or Halon 1301 gas in the event of a fire. An extensive discus- sion of the fire protection recommended for use with underground oil-filled transformers is included in the following report: 34 Buckley, J. L. , B. G. Vincent, and R. G. Zalosh (Factory Mutual Research). Improved Fire Protection for Stationary Underground Equipment. BuMines Open File Report 27-78, May 1976, 163 pp.; available from National Techni- cal Information Service, Springfield, Va., PB 280 136/AS. Silicone Transformer Liquid All liquid-filled transformers have better sustained overload capacity and short-term, high overload capacity than do dry type transformers. The greater heat capacity of liquids compared with air and other coolant gases used in transformers is the reason for this greater overload capability. The fire-resistant alternatives to askarels are mainly silicones and high- fire-point hydrocarbons of the paraffinic variety. A discussion on high- fire-point hydrocarbons follows. Silicone-f illed transformers are filled with low-viscosity polydimethyl siloxane liquid. Silicone fluids are nontoxic, have low flammability (though not quite as low as PCB's), and low solvency strength (which means that trans- formers filled with silicone can be expected to have very long service lives). The disadvantages of silicones are (a) even though the material is referred to as "low viscosity," silicone is more viscous than either oil or askarel, which means that silicone-filled transformers must be slightly larger than trans- formers of equivalent power capacity filled with askarel or oil; (b) on a vol- ume basis, silicone fluids cost about twice as much as askarel; (c) when silicone does burn, it releases clouds of amorphous silica that may create visibility problems; and (d) when used as a retrofill fluid, the poorer heat- transfer characteristics of silicone relative to askarel require the derating of the transformer by about 15 percent if the unit is likely to be run contin- uously at close to its original rated temperature. Silicone-filled transformers are not recommended for use in underground coal mines because silicone vapors will gradually deactivate methane detec- tors. Silicone liquids are also powerful defoamers, so large spills of trans- former silicone liquid onto ore that will be treated by floatation or into the water of a floatation plant may disrupt the operation of the process. High-Fire-Point Transformer Liquids The 1978 edition of the National Electrical Code has a new specification for high-fire-point liquid insulated transformers that reads: "Transformers, insulated with a nonpropagating liquid approved for the purpose, having a fire point not less than 300° C shall be permitted to be installed indoors or out- doors. Such transformers installed indoors and rated over 35,000 volts shall be installed in a vault." High-fire-point fluids for transformers are essentially of three varie- ties: (1) Natural, that is, derived from natural hydrocarbon fluids by refin- ing out everything but certain molecular species, uaually the long-chain paraffinic molecules; (2) synthetic hydrocarbon, that is, built up out of 35 simpler molecular species into long-chain paraffinic molecules; and (3) sili- cones. The hydrocarbon products are roughly the same, just derived by differ- ent processes. Factory Mutual has published the following installation and protection guidelines for transformers that contain high-fire-point liquids: Factory Mutual Engineering Corp. Less Flammable Transformer Fluids. Data Sheet 5-4S/14-8S, October 1979; available from Factory Mutual Engineering Corp., 1151 Boston-Providence Turnpike, Norwood, Mass. 02062, telephone 617-762-4300. The minimum allowable distances between the edges of the diked area and the adjacent walls and the minimum allowable ceiling height are specified based on the size of the diked area and the rate of heat release from a pool fire of each specific transformer liquid. Factory Mutual has measured heat release rates from the various liquids that are commercially available, and this information is included in the Data Sheet. There are a number of questions not yet satisfactorily answered concern- ing the use of the high-fire-point transformer liquids. The most important question concerns the realism of the test conditions. It has been suggested that catastrophic arcing followed by case rupture is a relatively unusual mode of transformer failure and that a more frequent problem is prolonged minor arcing that generates flammable gases from the breakdown of transformer fluid. The flammability of unused liquids may not be a reliable indication of their relative safety under actual transformer operating conditions. The fire point of the synthetic hydrocarbon high-fire-point fluid is about 310° C; for the refined high-fire-point hydrocarbon it is about 312° C; and for silicone it is 360° C. The high-fire-point of the paraffinic hydro- carbon fluids is a result of the relatively high molecular weight of the hydrocarbon material. The inherent disadvantage of the high molecular weight is higher viscosity and thus lower heat-transfer capability than either ordi- nary mineral oil or askarel. The major advantages of the high-fire-point flu- ids are their low price relative to silicone and askarel and their inherent biodegradability. Open Air-Cooled Transformers Transformers can be built without the use of a liquid cooling medium. One type of dry transformer that is quite successful under limited conditions is the open air-cooled transformer. In this design, the required cooling is provided by air that passes through the transformer as a result of either thermal convection or forced fan circulation. In those sizes where air-cooled transformers are available, they are about equal in price to askarel-f illed transformers of the same kva rating. However, the following limitations gov- ern the successful use of open air-cooled transformers and prevent them from being considered for many applications using askarel-f illed transformers. 36 Heat Capacity : The power drawn from a transformer usually varies over a fairly wide range. The rating of a transformer is basically governed by the power it can handle continuously without overheating. If a liquid-filled transformer is operated at overload conditions for a short period of time, the liquid will act as a heat sink, absorbing the excess heat produced in the transformer without a rapid increase in temperature. The result of this ther- mal inertia is that liquid-filled transformers can operate at outputs of up to 200 percentr of rated capacity for a period of 1 to 2 hours without being damaged. An air-cooled, dry-type transformer does not have this heat sink availa- ble and is limited to operating at a maximum service rating near its contin- uous rating. Where the current drawn on the transformer does not vary greatly during the day, this limitation is no problem. However, in most cases the variation in load would require that a dry transformer be sized 20 to 30 per- cent greater in capacity than a liquid-filled transformer for the same application. Dielectric Strength : The liquid coolant in a liquid-filled transformer also provides a significant level of electrical insulation between the various current-carrying components within the transformer. Air has a much lower dielectric strength, and open air-cooled transformers are limited to a maximum voltage of 25 to 40 kv. The problem of electrical insulation is even more severe if the open air-cooled transformer only operates intermittently. When the transformer is operating, the heat generated within the windings keeps their insulation dry and maintains a high dielectric strength. However, when the transformer is not operating, the coils cool to ambient temperatures and the insulation can absorb moisture from the air, which reduces its dielectric strength. Therefore, an open air-cooled transformer must be carefully dried before being put into service after each time it has been allowed to cool. One final problem with dry air-cooled transformers is due to the tendency of dust to be attracted from the air to the coils by electrostatic attraction. This dust can build up in the coils, which blocks the flow of air and causes overheating, or the dust can form conductive paths that short circuit the transformer. Dry, open air-cooled transformers are generally limited to dry, clean locations where the load requirements are fairly even and constant, and where the maximum voltage does not exceed 30 kv. Sealed Gas-Filled Transformers A dry transformer can be provided complete protection from environmental effects by sealing it is a pressure-tight container and using an inert gas as the coolant. Gas-filled sealed transformers have the same overload limita- tions as dry air-cooled units, but better control of the insulating media raises the maximum achievable voltage to levels available with liquid-filled units. 37 Several different gases have been used as the coolant in sealed gas- filled transformers. The commonly used gas in the United States is hexafluor- oethane (C 2 Fe). Although chlorof luorocarbons are regulated by the EPA, the use of this gas in transformers will probably not be affected by the regula- tions. Nitrogen and sulfur hexafluoride have also been used successfully as transformer coolants in certain applications. Because the inert gas increases in pressure when heated, a gas-filled transformer must be enclosed in a heavy pressure vessel housing. The pressure vessel increases both the size and weight of the gas-filled transformer com- pared with that of open air-cooled units. The price of the sealed gas-filled units is also considerably higher than that of open air-cooled units. Because of the poorer heat-transfer characteristics of the gas compared with liquids, the gas-filled transformers are designed to operate at 150° C coil temperature rise and have insulation systems limited to 220° C. Hot spots in the coils can approach 220° C; accordingly, there is no allowance for even short-term operation at loads higher than rated capacity. Therefore, the gas-filled transformers must often be specified in a larger size than the liquid-filled transformers to allow for the expected heavy load peaks of power consumption. Cast Coil Transformers The third class of dry transformer is the cast coil type. Cast coil transformers have had their primary windings or both their primary windings and their secondary windings totally encapsulated in vacuum-degassed epoxy resin. This type of construction decreases the noise level in comparison to other dry type transformers, and because of the thermal capacity of the encap- sulating epoxy, the overload capacity approaches that of liquid transformers while the fire safety advantage is about the same as that of other dry transformers. Cast coil transformers are generally more compact, lighter, and more shock resistant than either liquid-cooled or the other dry-type units. The exceptional thermal performance (comparable with that of liquid transformers in terms of running temperatures and overload capability) is achieved by reducing resistance losses in the coil conductors. This significantly increases manufacturing costs and initial price, but it results in decreased electrical operating costs and is a factor in the probably longer life of these units. This technology is better developed in Europe than in the United States. Although the cast coil transformers are among the most expensive in terms of initial cost, they are gaining increased usage where reliability, small size, and fire safety are important consideration. Mining Machinery Transformers Draglines, shovels, and blasthole drills that are electrically powered use transformers to reduce the incoming high voltage to the levels used by the drive motors. In some instances, the machinery was originally designed for oil-filled transformers. When askarel transformers were specified by the buyer, they were installed in the fire-resistant vaults that had been designed 38 for oil-filled transformers. In some cases where these customer-ordered aska- rel units fail, they can be directly replaced with oil-cooled transformers with little, if any, increase in fire hazard. In the event that an insurance carrier requires fire safety in addition to an onboard vault, there is likely to be no great difficulty in installing a silicone or high-fire-point, hydrocarbon-cooled transformer. In those instances where an item of mobile machinery was actually designed with askarel transformers in mind, the installation of oil-filled transformers might not be possible because of the lack of fire safety precau- tions, such as fireproof vaults. Gas-cooled transformers might be adequate replacements for askarel transformers, except that gas-cooled units are gener- ally slightly larger in physical dimensions then comparable kva liquid-cooled units. Silicone and high-fire-point hydrocarbon transformers might satisfy most safety requirements at slightly higher cost than the original askarel units. Several other alternatives to the use of askarel transformers on mobile machinery were observed during the mine visits. On one dragline, there were several oil-filled transformers, each in a steel room with appropriate vents. Each room was equipped with a fire detection system that would set off an alarm in the operator's cabin if a fire occurred and would also activate a Halon 1301A fire suppression system. A second dragline, still under construc- tion, had two large three-phase oil-filled transformers mounted on platforms on the exterior of the machine, thereby minimizing the damage that a trans- former fire could cause. A third possible alternative was under consideration for a transformer on a blasthole drill. This transformer was mounted on the rear of the machine and, in the event of a fire, could have posed a consider- able threat to the operator. Mine personnel were planning to remove the transformer from the drill and mount it nearby on skids so that the trans- former posed less of a hazard but could still be moved as required. Though this particular transformer was oil filled, this same procedure could be done any time an askarel transformer needed to be replaced on any type of machinery with a slight increase in electrical resistance losses. Relative Costs of Non-PCB Replacement Transformers The National Electrical Code allows only the smallest of oil-cooled transformers to be used indoors without a vault. The cost of a vault can increase the installation cost of an oil-filled transformer in place of an askarel unit by 90 to 133 percent of the base cost of the transformer, thereby eliminating the use of oil-filled transformers for askarel units where no vault already exists. At voltages in excess of 35 kv, the code requires that all types of transformers be installed in vaults if they are located in build- ings. However, as far as the mining industry is concerned, it is unlikely that many transformers will be installed in indoor locations handling more than 35 kv. Therefore, the cost of vault construction will be considered here in connection with oil-cooled transformers only. 39 Table 4 summarized the relative basic costs and installed costs of vari- ous types of transformers. Askarel transformers are included for the sake of comparison. TABLE 4. - Cost comparisons of oil-filled versus other transformer designs intended for hazardous locations, percent (1,000 kva, 15 kv transformer) Type First cost Vault Catch Basin Vent Total Installed cost Oil Askarel (1976) High-fire-point hydrocarbon liquid High-fire-point silicone liquid Dry open coil air-cooled.... Dry gas-filled Dry cast coil 100 140 120 140 150-170 200 150-170 90-133 NAP 10 110 110 190-233 150 120-130 150 150-170 200 150-200 ^atch basin is not required by law or regulation but is required as a condition for insurance coverage by certain industrial insurers. Sources: Westinghouse Electric Corp. p. 18 (updated). Is There Another Way? Sharon, Pa. Deaken, R. F. J., and P. D. Smith (Polygon Industries Ltd.). Epoxy Insulation — A New Generation of Dry Type Transformers. Pres. at 64th Ann. Meeting, Canadian Pulp and Paper Assoc, Montreal, Quebec, Canada, Jan. 31, 1978. Summary — Considerations in Choosing an Alternative to PCB Transformers The following considerations apply to all situations in which trans- formers are used in mining; that is, aboveground, underground, indoor, or on mobile machines. Oil-Cooled Transformers : There are surprisingly large numbers of trans- former installations, in mining and in other industries, where askarel trans- formers have been installed in places where the prevailing electrical code as well as common sense would have allowed the installation of oil-filled trans- formers. If such an askarel transformer must be replaced, either because it has failed or because in its present location it is too costly or virtually impossible to secure against fluid loss (and therefore presents a potential extreme cleanup threat), the first choice to be considered is an oil-filled unit. If the use of an oil-filled transformer presents no particular fire hazard, and if no additional fire precautions are needed such as a vault, then the oil-filled unit will be the most cost effective and the easiest replacement. 40 Silicone and High-Fire-Point Transformers : Because the coolant fluids in silicone and high-fire-point type transformers are of a higher viscosity than either askarel or ordinary transformer mineral oil, their heat-transfer char- acteristics are not quite as good. Thus replacement transformers of these types are likely to be slightly larger than the askarel units they replace. They will probably not be as heavy as the equivalent askarel units, however, because of the extremely high density of the askarel coolant. Silicone. and high-fire-point, hydrocarbon-cooled transformers find their best applications as replacements for askarel transformers in places where fire vaults for oil- filled units would either be too expensive to install or would be impractical to install because of space limitation. Being liquid filled, they have the advantage of having high sustained overload capacity, the same as askarel and oil-filled transformers. Dry Type Transformers : Dry, open air type transformers are usually larger than liquid-cooled units because of the allowance that must be made for air movement. And assuming that the unit is used in an environment where dust is not a consideration, open air-cooled transformers can operate with less maintenance than any of the liquid type transformers. Open air-cooled trans- formers have two drawbacks as far as mining is concerned: They have only short-term overload capability because they contain no liquid to act as a heat sink, and they -tend to generate much more noise than liquid-filled trans- formers, which can be irritating to people who have to work nearby. Sealed gas-cooled transformers have all the same characteristics of open transformers, except they are totally sealed against the hazards of environ- mental dust and corrosive gases and fumes. Since they are sealed, their cases have to be of heavy-gage construction to contain the pressure of the gas inside when the unit is operating at high temperatures. Thus they tend to be heavy as well as large in comparison with liquid units of equivalent rating. Their chief advantage is their almost total freedom from maintenance, which makes them suitable for applications where maintenance is impractical. Their disadvantages include high initial cost, high operating noise, and poor sus- tained overload capacity. Cast coil transformers have advantages of both liquid and dry trans- formers. They require virtually no maintenance, they produce noise levels that are intermediate between liquid and other dry units, and because of their designed-in high efficiency plus the amount of material used to encase the windings, they can sustain high overloads almost as well as liquid-filled transformers. Their main disadvantage is high initial cost. PCB-CONTAMINATED TRANSFORMERS About 98 percent of the liquid-filled transformers in use in the United States (probably including the majority of those used in mining applications) are filled with transformer oil. Analysis of oil taken from several hundred transformers owned by electrical utilities has indicated that as many as 38 percent of all of the oil-filled transformers may be contaminated with PCB's in concentrations exceeding 50 ppm (that is, 0.1 lb PCB ' s per ton of oil). The contamination of transformer oil with PCB's may have occurred 41 either in transformer manufacturing plants where both PCB's and oil were used to fill transformers, or in routine field servicing that involved filtering the liquid by use of equipment that was used for both oil- and askarel-filled units. In a few cases, PCB's may have been used to top off oil-filled transformers. PCB's are completely soluble in transformer oil, and there is no easy way to determine whether low levels of PCB's are present in any particular lot of oil at concentrations above 50 ppm. The only feasible method for analyzing for low levels of PCB's in oil involves the use of a gas chromatagraph with an electron capture detector. A number of qualified analytical laboratories will perform this analysis for prices ranging from $60 to $100 per sample depending on the number of samples submitted at one time. The EPA regulations on PCB's define "PCB-contaminated transformers" as any oil-filled transformer in which the oil is contaminated with PCB's in con- centrations above 50 ppm, or as any oil-filled transformer in which the oil has not been tested and found to contain less than 50 ppm PCB's. In other words, all oil-filled transformers must be considered to be contaminated with PCB's unless tests must have been performed and the oil found to not contain PCB's. Transformer oil known to be contaminated with more than 500 ppm PCB's is classified as a PCB askarel; both the oil and the transformer that it is in are considered to be PCB askarel items and are covered by the regulations. Transformer oil that contains 50 to 499 ppm PCB's or that has not been tested is considered to be PCB contaminated. EPA regulations apply to the disposal or reuse of contaminated oil, but there are no regulations on the continues use, maintenance, rebuilding, or disposal of the transformers. Transformer oil that is known by test to contain less than 50 ppm PCB's is not covered by the EPA PCB regulation. Disposal of transformer oil from PCB-contaminated transformers: By incineration in an approved PCB incinerator; li+ by burial in an approved PCB chemical waste landfill; by burning as an auxiliary fuel in a large power boiler that meets specific operational requirements (see regulations for details). Reuse of oil from PCB-contaminated transformers: Reclamation and reuse of oil is allowed by the owner of the oil. Resale of used or reclaimed oil from PCB-contaminated transformers: Banned. Storage of out-of-service PCB-contaminated transformers or oil from such units: Must be in a facility meeting the requirements of SPCC plan. 1H As of January 1981 EPA has not approved any incinerators for commercial disposal of PCB's. See General Requirements, subsection on Disposal. 42 Spill cleanup : All material contaminated with more than 50 ppm PCB's must be picked up and disposed of as PCB's. In general, the oil spill regula- tions will apply and will be more stringent for low-level contamination of land and water by oil. PCB CAPACITORS Most AC power capacitors manufactured in the United States between 1935 and 1977 used PCB's as a dielectric liquid. The EPA regulations banned the sale of PCB capacitors after July 1, 1979, unless the seller has obtained an exemption from the regulations from the EPA. However, non-PCB capacitors have been developed for almost all of the applications where PCB units were pre- viously used. The liquids used to replace the PCB's in these new designs are more flammable than PCB's, but the manufacturers have developed various pressure-sensitive and heat-sensitive circuit breakers that prevent the capac- itor from rupturing if it fails electrically. The EPA regulations will allow existing capacitors to remain in service but impose certain marking, recordkeeping, storage, disposal, and spill cleanup requirements. 4Jses of PCB Capacitors in the Mining Industry Electronics : Small PCB capacitors were used in the power circuits of some microwave ovens and television sets. Motor Start Capacitors : Used in series with the secondary windings of larger single-phase motors such as those used in room air conditioners and submersible well pumps. Ballast Capacitors : Used in the ballasts of fluorescent lights and high- intensity mercury are arc and sodium arc lamps. Power Factor Capacitors : Usually located in substations, although often found on distribution poles. Surge Capacitors : Used with circuit breakers in large electric motors and on load centers. How To Identify PCB Capacitors Liquid dielectric type AC capacitors are sealed metal cans with two or more terminals. The non-PCB capacitors that have been built since July 1, 1978, have all been marked "No PCB's." All other capacitors of this type must be assumed to contain PCB's unless you know, based on manufacturer's litera- ture or label information, that a specific capacitor does not contain PCB's. The following is a list of the manufacturers known to have produced PCB capacitors since 1971. PCB capacitors manufactured prior to 1971 may not appear on this list if the manufacturer stopped using PCB's or went out of business. 43 Manufacturers Trade name of liquid Aerovox Hyvol Axel Electronics NA Capacitor Specialists NA Cornell Dubilier Dykanol Electrical Utilities Corp Eucarel Electromagnetic Filter Co NA General Electric Pyranol Jard Corp Clorphen McGraw Edison Elemex P. R. Mallory and Co Aroclor B R. F. Interonics NA Sangamo Electric Co Diaclor Sprague Electric Co Clorinol Tobe Deutschmann Laboratories NA Universal Manufacturing Corp Askarel Westinghouse Inerteen York Electronics ? NA Not available. Requirements for PCB Capacitors PCB capacitors may continue in use indefinitely, with no special diking provisions required. The PCB regulations define three types of PCB capaci- tors, and different requirements apply to each type: Types of PCB Capacitors : Small: Contain less than 3 lb PCB's (exempted from all requirements ) . Large High Voltage: Contain more than 3 lb PCB's and operate at voltages above 2,000 v (basically distribution system power factor capacitors). Large Low Voltage: Contain more than 3 lb PCB's and operate at voltages below 2,000 v. Note: In general, "large" capacitors are those having a can volume greater than 300 cu in. Use : No restrictions on continued use of existing PCB capacitors. Marking : Large High Voltage: A PCB label must be applied to each capacitor in use and in storage. Large Low Voltage: A PCB label must be applied to each capacitor when it is removed from service. It would probably simplify the 44 job of keeping track of the large PCB capacitors if the large low-voltage capacitors in service had the label applied, but this is not required. Small: No marking requirements. Recordkeeping : Required, except for those facilities having fewer than 50 large capacitors and no other PCB transformers. The records for capacitors must include the following information: The total number of PCB large high- voltage and low-voltage capacitors in the facility; the date each large PCB capacitor is removed from service, is placed into storage for disposal, and is placed into transport for disposal; for large capacitors removed from service, the location of the initial disposal or storage facility and the name of the owner or operator of the facility; for PCB capacitors in storage in contain- ers, the total weight of capacitor in each container. An annual report must be prepared summarizing this information as of July 1 of each year. All records must be retained for 5 years after the facility ceases using or stor- ing PCB's. Storage for Disposal : Requirements apply to storage of large PCB capaci- tors only. In general, capacitors must be placed in drums and stored in spe- cial PCB storage" areas. However, nonleaking large capacitors may be stored on pallets next to an approved storage area until January 1, 1983, provided that (1) the storage area has immediately available unfilled storage space that could accommodate at least 10 percent of the capacitors stored outside the area (in case a capacitor should start to leak, it could be immediately moved into the storage area) and (2) the capacitors on pallets are inspected weekly. Disposal : Large PCB Capacitors: In an approved PCB landfill until March 1, 1981, capacitors must be shipped in steel drums that meet DOT requirements, and void spaces must be filled with sawdust, dirt, or other absorbent material. The use of PCB landfills for dis- posal of capacitors may be allowed after March 1, 1981, if no suitable approved incinerators are available. Check with EPA after March 1, 1981, to determine disposal requirements (toll- free, 800-424-9065). Small PCB Capacitors: No special disposal requirements. May be disposed of as any other trash. Spill cleanup: It is uncommon, but not unknown, for a capacitor to leak when it fails. Because of the high temperatures and pres- sures caused by an electrical arc occurring inside a capacitor, PCB vapors may be vented under pressure and spray over a consider- able area. The regulations require that all material contaminated with over 50 ppm PCB's be picked up and disposed of in an approved PCB landfill, and that contaminated surfaces of equipment be decontaminated. Rupture of a capacitor in an underground or 45 indoors application could result in high concentrations of PCB's in the air, which would present a serious health hazard to any workers in the area. Precautions for Continued Use Capacitors seldom rupture when they fail, and there is little likelihood that a major PCB spill will result from the failure of any PCB capacitor pres- ently in service. Even a large power factor capacitor rated at 200 kvar will contain only about 40 lb of PCB's, and most of this is adsorbed in the paper or other solid dielectric material. Therefore, the maximum amount that could leak out would probably not exceed 8 lb of PCB's. In the infrequent occasion of a rupture of a capacitor, PCB's will probably be sprayed out as a fine mist. This will contaminate nearby objects and materials, and the contami- nated material will have to be picked up and disposed of as PCB's. The only significant risk that could result from continued use of PCB capacitors would be human exposure to PCB vapors if a capacitor failed in a building or underground installation. Most capacitors used in these environ- ments are used as surge protection on distribution transformer primary termi- nals and on motor contactors. In most cases, system electrical safety can be improved by removing the capacitors and installing properly sized surge arrestors. This system modification is discussed in more detail in the fol- lowing section. Substitutes for PCB Capacitors PCB's are no longer being used in capacitors, and the EPA regulations ban the sale of PCB capacitors after July 1, 1979, unless the seller has applied for and been granted an exemption from these ban requirements. Capacitors using non-PCB dielectric liquids are available for most applications. Although the replacement liquids do not have the fire resistance of PCB's, the manufacturers are improving the rupture resistance of non-PCB ballast capaci- tors by building thermal and pressure-sensitive circuit breakers into the capacitors. Most large high-voltage power factor capacitors are located out- doors at substations, and there is little risk of major fire damage even if a leak should occur and the liquid burn. The capacitors used in buildings and in underground mines on the primary terminals of distribution transformers and associated with motor contactors can present a potential fire problem if non-PCB capacitors are used. These capacitors are used to limit the rate of voltage rise and to protect the cir- cuit breaker from flash over resulting from chopping when a motor is discon- nected. However, recent research has shown that capacitors used in these applications may actually degrade the electrical system performance. The presence of too much load side capacitance can result in prestrike when a motor contactor is closed; the capacitor should be installed on the motor terminals rather than adjacent to the contactor as is usual practice — the inductance of the cable will help reduce the tendency of prestrike. In addition, the charging requirements of excess capacitance can trip out the 46 ground fault detector in some cases. In most cases, improved system safety can be achieved by removing the capacitors and installing low sparkover dis- tribution class surge arrestors that are coordinated with the insulation char- acteristics of the associated motor and transformer. The factors that must be considered in making this system change are discussed in detail in the follow- ing report: Morley, L. A., and others (Pennsylvania State University). Coal Mine Elec- trical System Evaluation. Volumes I through VII. BuMines Open File Rept. 61-78 (set), 1977, 1,015 pp. Available for reference at BuMines facilities in Denver, Colo., Twin Cities, Minn., Bruceton and Pittsburgh, Pa., and Spokane, Wash.; U.S. Dept. of Energy facilities in Carbondale, 111., and Morgantown, W. Va.; National Mine Health and Safety Academy, Beckley, W. Va.; and National Library of Natural Resources, U.S. Dept. of the Interior, Washington, D.C.; available from National Technical Informa- tion Service, Springfield, Va., PB 283 489/AS (set); contract G01 55003. UNDERGROUND MINING MACHINERY Use In the late 1960's and early 1970' s PCB's were used in some electric motors manufactured by Reliance Electric for Joy Manufacturing Co. Joy used these motors in the following applications: CU43 continuous miners — cutting-head motors, pump motor 9CM continuous miners — cutting-head motors, pump motor 14BU10 loaders — traction motors Liquid-filled motors were used because they were smaller and lighter than air-cooled motors. A PCB mixture was chosen as the liquid because it was non- flammable, provided adequate lubrication, and possessed the best overall com- bination of electrical properties, chemical stability, and cost. The amount of PCB's used in each of the various kinds of motors is summarized in table 5. TABLE 5. - Quantity of PCB's in mining machinery Machine Weight of fluid per motor Weight of fluid per machine kg lb kg lb 20.9 26.1 20.9 46.0 57.5 46.0 62.7 78.3 41.8 138.0 172.5 92.0 Identification All of the CU43's, 9CM's, and 14BU10's originally sold by Joy used PCB- filled motors. Some of the traction motors on the loaders have been converted to air cooling and are no longer affected by the PCB regulation. If one of 47 the loaders was purchased used, and there is some doubt about whether the motors still contain PCB's, the air-cooled motors can easily be identified because they have no fill-plug or pressure-relief valve. Some of the continuous miner motors have been converted to silicone cool- ing. The shop that performed the conversion should be contacted for informa- tion about the possibility of the motors being contaminated with small amounts of PCB's. If the repair shop does not have any information, the following guides should be followed; 1. If the motor was disassembled, degreased, and rewound , there is little or no chance that any PCB's remain; thus the motor would not be covered by EPA regulations. 2. If the motor was not rewound but was only drained, flushed, and refilled with silicone, there were probably still enough PCB's trapped in the motor windings to contaminate the silicone. In this case, the motor is cov- ered by the regulations and should still be treated as though it were filled with PCB's. The procedures and recommendations in this chapter should be followed. EPA Requirements All three types of equipment may be used until January 1, 1982, under the following conditions: 1. PCB's may be added to any of the motors until January 1, 1982. 2. PCB-filled motors on the loaders must be rebuilt as non-PCB motors the next time the motor is rebuilt. 3. PCB-filled motors on the continuous miners may not be rebuilt after January 1, 1980. 4. Any PCB's that will be used to service PCB-filled motors must be stored in accordance with the requirements previously listed. 5. PCB motors must be disposed of in an approved chemical waste land- fill. Disposal must take place before January 1, 1984. The regulations per- mit used machinery to be bought and sold. The EPA regulations require that labels be applied to anything that con- tains PCB's. In connection with the PCB-filled motors, the following things must be labeled immediately: 1. Each PCB-filled motor. 2. Each mining machine that still has a PCB-filled motor. 3. Each can of PCB's that is on hand for servicing or being stored for disposal. 48 4. Each area that is being used to store PCB's or PCB-filled motors. The labels should be placed where they can be easily seen. Recordkeeping : None required by the regulations. Servicing PCB's may be added to mining machinery motors until January 1, 1982. After this date, further use of the machinery is prohibited and any PCB's in stock must be disposed of properly. The motors on the continuous miners may be rebuilt until January 1, 1980. After that date the machinery may still be used (until January 1, 1982); if a motor fails and no spare motor is available, the machine must be retired and the motors must be disposed of properly. Disposal The regulations require that the motors be drained of as much liquid as possible, and the liquid must be shipped to an incinerator that has been approved by the EPA for disposal of PCB's. The drained motor must be disposed of by burial in""an approved chemical waste landfill. To obtain information on the location of approved incinerators and landfills call (toll-free, 800-424-9065, or in Washington, D.C., local 554-1404) or write the Office of Industry Assistance, Office of Toxic Substances TS-799, U.S. Environmental Protection Agency, 401 M St., S.W., Washington, D.C. 20460. The motor and the liquid must be disposed of before January 1, 1984. If the motor or the liquid will be kept for more than 30 days after the motor is removed from service, storage must be in an area that meets the requirements described above. Recommended Precautions for Continued Use The following precautions should be taken when using PCB fluids in mining machinery motors: 1. A pan filled with floor-dry, sawdust, or some other absorbent mate- rial should be placed under a motor before it is topped off. 2. Drips and spills should be avoided or promptly cleaned up when top- ping off a motor. 3. Motors should not be overfilled as this has, in some instances, resulted in leaks. 4. Any leaking motor or any motor that is using a greater than normal amount of fluid should be immediately removed from service until the cause of the loss of fluid is located and eliminated. 49 5. If a continuous miner is going to be used much past January 1, 1980, Joy Manufacturing Co. should be contacted as soon as possible to make arrange- ments to have the motor rebuilt before the January 1, 1980, deadline on rebuilding. Emergency Spill Response If PCB's leak or spray out of a mining machinery motor, the procedure described in appendix A should be followed. In addition, if the spill happens underground the following precautions should be taken: 1. If water is being sprayed on the mine face near the machine, the water should be shut off immediately. 2. If mine dewatering is being performed in the area of the spill, it should, if possible, be stopped immediately. (If the dewatering system becomes contaminated with PCB's, it will have to be thoroughly cleaned or pos- sibly sent to a chemical waste landfill. ) Non-PCB Replacement Equipment Loaders The traction motors on the loaders can be rebuilt as air-cooled motors. Joy Manufacturing will do this for approximately $3,100 per motor. This is roughly what it would cost for rebuilding the motor for continued PCB-cooled operation. The EPA regulations do not permit the motors to be used after January 1, 1982, and also do not permit Joy to perform the conversion to air- cooling after January 1, 1982. For further information on having the conver- sion performed, contact the nearest Joy sales representative or service facility. Continuous Miners There is no suitable replacement for the PCB-filled motors on the contin- uous miners. The motors cannot be rebuilt for air-cooled operation because there is not enough room in the machinery frame. Some of these motors have been refilled with a silicone fluid. The use of silicone fluids has not been approved by MSHA because silicone vapors will deactivate methane detectors, and is not recommended by Joy because the silicones will burn. Therefore, silicone fluid cannot be considered an acceptable replacement for PCB's in these motors. The only acceptable alternative is to purchase another miner before the January 1, 1982, deadline. ELECTROMAGNETS Use Most separator electromagnets are filled with mineral oil, but PCB's have been used in magnets mounted in locations where there is an increased danger of fire. These PCB-filled magnets have been used primarily indoors near coal crushers and over conveyors at the head of a mine, though they may be found in other locations. 50 Identification There are no markings on a magnet that tell whether it is filled with mineral oil or PCB's; PCB's were simply substituted for mineral oil at the request of the purchaser. The simplest way to determine what a magnet is filled with is to check company records. If records are not available, the serial number of the magnet should be obtained from the nameplate and the manufacturer should be contacted. Three manufacturers used PCB's in some of their magnets: Dings Co. 4780 West Electric Ave. Milwaukee, Wis. 53246 414-672-7830 Eriez Magnets 95 Magnet Drive Erie, Pa. 16512 814-833-9881 Stearns Magnetics, Inc. 6001 South General Ave. Cudahy, Wis. 53110 414-769-8000 EPA Requirements PCB-filled electromagnets are considered to be totally enclosed uses of PCB's and are subject to the same requirements as PCB transformers, except for the recordkeeping requirement. Marking Any electromagnet that contains PCB's or liquid contaminated with over 50 ppm PCB's must be labeled. Recordkeeping : None required by the regulation. Servicing Minor servicing of PCB-filled electromagnets is permitted until July 1, 1984, but rebuilding or any other type of servicing that requires removing the coil is prohibited. The following requirements must be followed when servic- ing a PCB-filled electromagnet: 1. PCB's removed from the magnet must be either returned to the magnet, used in some other permitted application, or disposed of properly. The PCB material may not be sold. 2. Any PCB's that may be used to service or repair a PCB electromagnet must be stored in an area that meets the requirements previously described. 51 Disposal The regulations require that the PCB magnet be drained of as much liquid as possible, and the liquid must be sent to an incinerator that has been approved by the EPA for disposal of PCB's. The drained magnet must be buried in an approved chemical waste landfill. To obtain information on approved incinerators and landfills, call (toll-free, 800-424-9065, or in Washington, D.C., local 554-1404) or write the Office of Industry Assistance, Office of Toxic Substances TS-799, U.S. Environmental Protection Agency, 401 M St., S.W., Washington, D.C. 20460. Before the liquid is drained from the magnet, the ground or floor under- neath should be covered with a sheet of plastic and a layer of floor-dry, saw- dust, or other absorbent material. If the magnet does not have a drain plug, a hole should be drilled or cut in one corner of the top of the magnet and the fluid should be siphoned into a barrel or drum that meets the requirements described above and that is acceptable to the incineration facility that will be receiving the fluid. Some incinerator operators may require that small drums of liquid be packed inside of larger barrels of sawdust to provide more protection against spills, so the incinerator facility should be contacted to determine its requirements. After the magnet has been thoroughly drained, the siphoning hose should be placed inside the magnet case and the hole should be plugged to prevent any small amounts of PCB's that remain in the magnet from leaking out when the magnet is sent to the landfill. If any PCB's dripped onto the layer of floor-dry, the contaminated material and, if necessary, the plastic must also be sent to the landfill. For additional information on transportation of PCB's see General Requirements. Recommended Precautions for Continued Use Precautions should be taken to reduce the possibility of spills and leaks when using a PCB-filled electromagnet. These steps include: 1. Inspecting the magnet at least once a month for minor leaks, with particular attention being paid to the welds, where cracks may develop if the magnet is frequently turned on and off. 2. If the magnet is being moved, extra care should be taken to insure that the casing is not damaged. The EPA regulations allow continued use of PCB-filled separator magnets over coal conveyors because it is assumed that any PCB's that leak out of the magnet will be destroyed when the coal is burned. However, the use of PCB magnets over coal that will be washed or otherwise subjected to water-based physical cleaning processes risks a major PCB contamination incident. Washing coal that has been contaminated with spilled PCB's will result in PCB contami- nation of the wash water, exposure of workers to PCB's vaporized from the recycled water, and stream pollution when the water is discharged from the plant. A major spill of PCB's into the water of a coal cleaning plant, 52 whether directly or due to contamination of the feed coal, would have to be considered an environmental disaster that would be extremely expensive, if not impossible, to clean up. The consequences of a possible PCB spill should be carefully considered when deciding whether to allow a PCB separator to remain in service. Emergency Spill Response If a PCB-filled magnet develops a leak, the spill response plan in appen- dix A should be followed. In addition, the following steps should be taken: 1. The conveyor should be stopped immediately to limit the amount of coal that becomes contaminated. 2. The magnet should be removed from over the conveyor, and a pan of sawdust or floor-dry should be placed on the conveyor under the leak. 3. Any visibly contaminated coal should be removed from the conveyor and placed in a drum for disposal. 4. See General Requirements for decontamination procedures. Non-PCB Electromagnets Several alternatives to the use of PCB-filled electromagnets are availa- ble. Oil-filled magnets can be used if there is a location where the increased fire risk would not pose a significant threat. The magnet manufacturers also sell silicone-filled magnets for use where a fluid with fire-resistant properties is required. A silicone-filled elec- tromagnet costs 40 to 50 percent more than a comparable oil-filled unit. The use of silicone fluids underground is not recommended because silicone vapors will deactivate methane detectors. Although the silicone fluid is nontoxic, major spills onto coal (or ore) prior to wet flotation processing may disrupt the process because silicone is a powerful antifoaming agent. Other high-fire-point hydrocarbon transformer liquids might also be con- sidered. These have about the same fire-point characteristics as silicone, but they release more heat than silicone if they do ignite. Repeated refilling of existing PCB separator magnets with transformer oil, silicone, or high-fire-point transformer liquid will gradually reduce the residual levels of PCB's. If the concentration of PCB's is reduced to below 50 ppm, the magnet would be allowed to be rebuilt or sold for scrap when it fails. (The regulations allow these alternatives for transformers containing less than 500 ppm PCB's. Rebuilding or scrapping a magnet having PCB's pres- ent in the fluid in concentrations between 50 and 500 ppm would require the owner to apply to the EPA for an exemption based on the precedent established for transformers.) 53 Dry-type separator magnets are also available. Eriez sells an air-cooled magnet that has been approved by Underwriters Laboratory for use in dirty, dusty environments. This type of magnet costs 20 to 25 percent more than a comparable oil-filled unit. HEAT -TRANSFER FLUIDS Use Because of their fire resistance and stability, PCB's were used as the major component of several high-temperature heat-transfer fluids. These fluids were manufactured from 1930 through 1972 by Monsanto. From 1972 through 1974 Geneva Industries of Houston, Tex., manufactured one type of PCB-based heat-transfer fluid. Monsanto quit selling PCB-based heat-transfer fluids during 1971-72, but it was several years before all the fluid was in the hands of the final consumer. Most purchasers of heat-transfer fluids were advised by Monsanto to drain their systems and refill them with a different fluid. Recent tests on a number of heat-transfer systems have found PCB's present at levels high enough to be regulated by the EPA even in systems that have been drained and flushed. PCB-based heat-transfer fluids manufactured by Monsanto are shown as follows: Therminol FR-0; Therminol FR-LO; Therminol FR-1; Therminol FR-2; Therminol FR-3. EPA Requirements Use : Heat-transfer systems containing fluid contaminated with more than 50 ppm PCB's may be used until July 1, 1984, provided that: 1. Every heat-transfer system that ever contained PCB-based fluid had to be tested by October 1, 1979, to determine the concentration of PCB's remaining in the fluid. 2. If the concentration of PCB's exceeds 50 ppm: (a) The system must be drained and refilled with fluid free of PCB's within 6 months. The PCB-contaminated fluid must be properly stored and disposed of in an approved PCB incinerator. (b) The testing and refilling procedure must be repeated annually until the concentration of PCB's is found to be less than 50 ppm at least 3 months after the most recent replacement of fluid. (c) Records of the testing and refilling must be maintained for at least 5 years after the concentration of PCB's is reduced to 50 ppm. 54 Marking Any heat-transfer system that contains a fluid with over 50 ppm of PCB's must be marked immediately. The label should be placed where it can be easily seen. Names and addresses of label printers are listed under General Requirements. Recordkeeping All records resulting from any test conducted to determine the PCB con- tent of the fluid in a heat-transfer system must be kept for at least 5 years after the system is determined to have a concentration of PCB's in the fluid of less than 50 ppm. Servicing Any type of servicing may be done on contaminated heat-transfer systems. The only restriction is that fluid containing 50 ppm or more of PCB's may not be used to refill or top off a system. This includes fluid that has been removed from a system during servicing. Fluid containing over 50 ppm of PCB's may be processed in some manner to reduce the level below 50 ppm, and then the fluid may be used in a heat- transfer system. This processing may be done by the owner of the system or by someone who has received authorization from the EPA to perform this type of servicing. Any fluid removed from a system that contains any level of PCB's must either be processed or disposed of in an approved incinerator. Some land- fills may accept liquids with less than 50 ppm PCB's for disposal. Fluid contaminated with any detectable amounts of PCB's may not be used for road oiling, as an herbicide carrier, or in any other similar application. Disposal When a PCB-contaminated (above 50 ppm PCB's in the fluid) heat-transfer system is taken out of service and will no longer be used, the fluid and the system must be disposed of separately. The fluid must be sent to an approved PCB incinerator. The drained heat-transfer system must then be disposed of by burial in an approved chemical waste landfill. Once the system is drained, it must be carefully disassembled for ship- ment (unless it is possible to ship the system whole). Plastic and floor-dry should be placed under each joint before it is taken apart. The landfill and the shipping company should be contacted for instructions on packaging por- tions of the system that are too large to fit in 55- or 110-gal drums. All containers that hold contaminated liquids and parts of the system must be labeled. If any of the material is going to be stored for more than 30 days before it is shipped to the disposal site, it must be stored in an area that meets the requirements described in General Requirements. 55 Disposal of scrapped PCB heat-transfer systems in a chemical waste land- fill will be expensive. Present costs are about $8 per cu ft plus transporta- tion, and the owner of the machine also loses the scrap value of the metal. It may be cheaper to decontaminate the system using a solvent such as fuel oil, even though the contaminated solvent would require disposal in an approved incinerator. Recommended Precautions for Continued Use The following precautions are recommended when using a heat-transfer sys- tem that is contaminated with PCB's: 1. If a major leak in the system could reach the ground or any water drain, the system should be diked. 2. Any drains or cracks in the floor near the system should be plugged or patched. 3. If there are minor leaks in the system and it is impractical or impossible to repair them, a pan of floor-dry or sawdust should be used to catch the leakage. The pans should be emptied periodically. Contaminated floor-dry and sawdust should be accumulated in a drum. This drum must be marked, stored in an area that meets the requirements previously described, and disposed of in an approved chemical waste landfill. 4. The system should be checked at least once a month for leaks. 5. When servicing is necessary, pans of floor-dry or a layer of plastic and then a layer of floor-dry should be placed under all joints that will be disassembled or that could leak as a result of being stressed while working on a different part of the system. 6. When a pump, piping, or other component of a system is removed, the ends or other openings should be plugged with rags, or the other component should be supported on a rack, pallet, wooden slats, or in some other manner such that plastic or pans and floor-dry can be placed under all openings that may leak PCBs. Emergency Spill Response In the event of a leak from a heat-transfer system, the spill response plan in appendix A should be followed. In addition, the following steps should be taken: 1. The heat should be shut off. 2. Any pumps in the system should be shut off. 3. If the leak is in a high-pressure portion of the system, the pressure should be relieved as rapidly as possible. 56 4. The system should be drained below the level of the leak as rapidly as possible. Non-PCB Heat-Transfer Fluids When Monsanto discontinued the sale of PCB-based heat-transfer fluids in 1972, it made available a number of substitute fluids for high-temperature, low-pressure heat-transfer systems. Suitable fluids are also available from a number of other manufacturers. These fluids are mostly of the chemical type of alkylated aromatics and aromatic ethers. The non-PCB fluids have two disadvantages compared with the PCB-based materials: (1) The non-PCB fluids are flammable, and (2) they will oxidize upon prolonged exposure to air at high temperatures. As a result, conversion to non-PCB fluids requires that the expansion reservoir be sealed and blan- keted with an inert gas such as nitrogen to protect the fluid from oxidation. Direct-fired systems must be protected against a major fire resulting from a break in the fired tubes by installing a remotely controlled steam, Halon, or carbon dioxide quench system in the combustion chamber. Information required to design specific applications is available from insurance underwriters and from the National Fire Protection Association, 470 Atlantic Avenue, Boston, Mass. 02210, telephone 617-482-8755. HYDRAULIC FLUIDS Use PCB's were used as the basis of a number of fire-resistant hydraulic flu- ids sold prior to 1972. These fluids were used primarily in die casting machines and in various hot metal equipment in steel mills. This study did not identify any use of PCB-based hydraulic fluid in mining machinery or in mine-related operations. However, it is possible that PCB-based fluid may have been used to some extent in the raining industry, and the EPA regulations apply to all systems that ever used PCB-based fluid, including mine applications. Identification The only known supplier of PCB-based hydraulic fluid was Monsanto, which marketed a number of different types prior to 1972, under the following trade names: Pydraul A-200, Pydraul AC, Pydraul AC-28, Pydraul F-9, Pydraul 135, Pydraul 150, Pydraul 230, Pydraul 280, Pydraul 312, Pydraul 540, Pydraul 540-A, and Pydraul 625. EPA Requirements Any system that ever contained a PCB-base hydraulic fluid must be tested by October 1, 1979, to determine the concentration of PCB's remaining in the system. Requirements for recordkeeping, marking, flushing, and periodic test- ing of contaminated hydraulic systems are the same as for contaminated heat- transfer systems. Disposal of drained hydraulic sytems is not regulated if 57 the liquid contains less than 1,000 ppm PCB ' s ; flushing prior to disposal is required if the fluid contains over 1,000 ppm PCB's. Disposal of fluid con- taminated with over 50 ppm PCB's must be in an approved PCB incinerator. Non-PCB Hydraulic Fluids Most systems that used PCB-based fluids have been converted to fluids based on phosphate esters or to water-glycol mixtures. Performance has been satisfactory, although neither of these substitute materials has the fire resistance or oxidation resistance of PCB's. Analysis of phosphate-ester-based hydraulic fluids for residual PCB's will cost more than will similar tests on hydrocarbon-based fluids because the phosphate interferes with the equipment that is usually used to perform this analysis. There should be no special problems if you tell the analytical lab what type fluid is presently in the system. WASTE OIL Over 1 billion gal of used oil per year is collected for use as road oil or is reclaimed for use as lubricating oil. The used oil that is re-refined for use as lubricating oil often contains industrial oil such as used trans- former oil and hydraulic fluid that is contaminated with low levels of PCB's. As a result, much of the re-refined motor oil contains low levels of PCB's, and dissipative uses of even segregated motor oil can release PCB's into the environment. EPA Requirements The use of waste oil containing any detectible levels of PCB's as road oil, insecticide carrier, or other dissipative use is forbidden. The regula- tions do not define the analytical method to be used to check for PCB's, but the commonly used gas chromatagraph can easily detect PCB's at concentrations of 1 or 2 ppm in used oil. Recommendations The major impact of this ban on the use of PCB-contaminated waste oil will be on the oiling of mining roads. Alternatives to discontinuing road oiling included the use of carefully segregated used virgin motor oil, testing each batch of oil for the presence of PCB's (at a cost of $50 to $70 per batch), the use of synthetic soil stabilization chemicals, or the use of water for dust control. A synthetic material that may perform satisfactorily is Coherex, manufactured by Witco Chemical Corp. The manufacturer should be con- tacted for additional information and recommendations. Proper disposal of used oil will be required to prevent the release of low levels of PCB's into the environment. Used oil may be used as a fuel or re-refined without special handling provided that the oil contains less than 50 ppm PCB's. 58 APPENDIX A. --OUTLINE OF PCB SPILL RESPONSE GUIDE EMERGENCY SPILL RESPONSE GUIDE FOR POLYCHLORINATED BIPHENYLS (PCB's, Askarel, Pyranol, Inerteen, etc.) What are PCB's: PCB's are a nonflammable oil used as a coolant and electrical insulating fluid in some transformers, capacitors, and sepa- rator magnets and in electric motors on certain Joy continu- ous miners and loaders. Hazards: PCB's are a toxic environmental pollutant. Do not breathe vapors or get on skin. Do not allow spilled PCB's to get into drains, sewers, or other water. First Aid: Skin contact: Wash off with waterless hand cleaner using paper towers. Store contaminated towels for special dis- posal. Eye exposure: Flush with water. Vapor exposure: Get medical aid. Spill Response Spill from live electrical equipment: Disconnect power, call chief electrician (telephone ) Then try to plug leaks with rags, stick, or other material. All spills: Call (environmental engineer, mine superintendent, etc.) (telephone ) Protective Use plastic gloves to prevent contact with skin. Contami- clothing: nated gloves, clothing, shoes, etc., should be put into 55- gal drum for disposal as PCB's. Tools may be decontaminated by washing with solvent; dispose of solvent, rags, etc., as PCB's. Control spill: Dike major spills with dirt or other material. Soak up spilled PCB's with rags, straw, or other material. Do not let PCB's run into drains or water. Final cleaning: Check with (mine environmental engineer), at (telephone ) for detailed instructions. Disposal of PCB- Solids — load into 55-gal drums; label with PCB label; ship to Contaminated EPA-approved PCB chemical waste landfill. Liquids — drain Material and into 55-gal drums; flush equipment with solvent such as kero- Equipment: sene or fuel oil to remove as much residual PCB as possible; drain solvent into drums; apply PCB label and store in secure roofed area meeting EPA requirements until an approved incin- eration facility becomes available for the disposal of PCB's. FIGURE B-l BRAZE Copper plumbing pipe with cap and fitting. 59 APPENDIX B.— WATER-ONLY DRAINAGE SYSTEM 1 The drainage system described below is designed so that water can freely flow out of the diked area, while askarel (PCB) fluid that is denser than water will cause a silicone rubber "flapper valve" to float up into a position covering the drain hole. Figure 6 shows the complete water-only drainage system in side and top views, but without the filter screen system that covers the valve and keeps leaves and other particu- late matter from clogging the valve. The fabrication and installation sequences of the valve are as follows: 1. Cut a 4-inch-long, straight, undented section of 1/2-inch (ID) copper plumbing pipe. 2. Place a copper cap on one end and a copper fitting having a 1/2-inch male pipe thread on the other end and then braze (do not solder) the three pieces together to thoroughly seal the joints (fig. B-l). Brazing is neces- sary to allow for the additional high-temperature brazing processes that are necessary for adequate strength of the finished valve. 3. From a piece of 1/8-inch-thick copper flat stock, cut a strip that is 2-5/8 inches long and 5/8 inch wide. This will be the "valve face." Braze it onto the part above in this manner (as shown in fig. B-2) . VIEW A-A' 2 5/8" A'. FILL WITH BRONZE FOR ^ENTIRE LENGTH, BOTH SIDES VALVE FACE FIGURE B-2. - Valve face. i This appendix is reprinted with permission from the Naval Facilities Engi- neering Command and Versar, Inc. Any questions regarding the information in this appendix should be referred to Versar, Inc., 6621 Electronic Drive, Springfield, Va., 22151. It originally appeared in the following report: Versar, Inc. Guide for the Management of Askarel Transformers. Rept. to Naval Facilities Engineering Command, Alexandria, Va., March 1979, pp. 41- 49; contract NOOO-25-78-C-0020. 60 4. Drill a 3/16-inch hole as shown and then cut away excess metal around the hold and gently grind the entire surface of the valve face on fine emery paper backed by a flat surface to remove any unevenness of the face (fig. B-3). 5. From 1/8-inch-thick copper flat stock, cut two pieces measuring 3/8 inch by 5/8 inch and braze them onto the valve face in the position shown in figure B-4. 6. From 1/8-inch, flat copper stock, cut a rectangular piece measuring 2 inches by 6-3/8 inches. Bend it to the shape shown in figure B-5 to make the "guard plate." DRILL 3/16" 8/16" J5v 1/4" BOTTOM VIEW OF VALVE FACE FIGURE B-3. - Bottom view of valve face. VIEW A-A' A<^ 3/8"He^ A' f BRAZE BRAZE 5/8" FIGURE B-4. - Two pieces brazed on valve face. BEND LINE ■4" 2" 2 1/4" *k LJ e-^90 GRIND OFF EXCESS METAL AT THE ENDS, TO THE DIMENSIONS SHOWN FIGURE B-5. - Rectangular piece of copper for "guard plate." 61 7. Braze the "guard plate" to the main body of the valve as shown in figure B-6. 8. From 1/8-inch flat copper stock, cut a rectangular piece — the "valve rest" — measuring 5/8 inch by 3-3/8 inches, and braze it onto the valve in this position (see note 1 in fig'. B-7) . DRILL AND TAPE 1/4-20(2) 3/8" BRAZE BRAZE SIDEVIEW 3/8" 3/8" 3/8" FRONT VIEW O DRILL AND TAP 1/4-20(2) BOTTOM VIEW FIGURE B-6. - Brazing of "guard plate" to main body of valve. THE "GUARD PLATE" CAN BE BENT SLIGHTLY TO MEET THE VALVE REST FOR BRAZING A. 1/8"+- 1/8" VALVE REST ^BRAZE (NOTE #2: THE REASON THE "VALVE REST" SHOULD BE ROUGHENED IS TO LESSEN THE CHANCES THAT THE SILICONE "FLAPPER VALVE" WILL STICK TO THIS SURFACE, BECAUSE THEN THE FLAPPER WILL NOT FLOAT PROPERLY IF IT SHOULD EVER COME TO BE SURROUNDED WITH PCBs FROM THE TRANSFORMER.) BRAZE (NOTE #1: USE A COARSE WIRE BRUSH TO ROUGHEN THE UPPER SURFACE OF THE VALVE REST BEFORE BRAZING INTO PLACE.) FIGURE B-7. 'Valve rest. 62 VALVE FACE — 0.1900" +- 0.025" VALVE REST — * DRILL 1/8" + 3/16"-+ 1/16" HOLE-LOCATING JIG: t — i 3/8" D + 0.050" -0.00" fct FIGURE B-8. - Bearing support holes and hole-locating jig. 9. Drill a 1/8-inch hole through each of the two (bearing supports) in the location shown in figure B-8. (It might be useful to make an alineraent jig to facilitate the finding of the center for this hole; a schematic of the type of jig that might be useful is shown. ) 10. After all the brazing processes are finished, the copper will have a coating copper oxide scale. Remove the scale with a rotary wire brush, but be careful not to mar the smooth valve face. Use fine emery paper and light fin- ger pressure to remove scale from the valve face. If there are large irregu- larities on the valve face, remove them with a fine flat file or use fine emery paper backed with a solid flat surface. The flapper valve must have these dimensions (see fig. B-9) . There are several ways to make these probably being: 'flapper valves," the two easiest (a) On a smooth flat surface, pour out a 5/8-inch-wide, or wider, strip of the uncured silicone rubber; make it at least 5/16 inch thick. Locate the Teflon tube so that it is perpendicular to the strip and 5/32 inch (±0.020 inch) off the flat surface. When the rubber has cured, use a razor blade to cut the flapper valve into the required dimensions. The critical dimensions and characteristics are — 63 1/8" 3" 1 •V 5/32" 05/16" *T ^ f- #14 TEFLON TUBE (WALL THICKNESS = 0.016" ID = 0.064" TO 0.074") FIGURE B-9. - Silicone rubber for "flapper valve." J 1* 90 ^ i 5/32"-+0.020" k-5/32" -+ 1/32" FIGURE B-10. - "Flapper valve" as made by method (a). (1) One surface of the flapper must be very smooth in order to seal the drain hole tightly when PCB's are present in the diked area. (2) The location of the Teflon tube must be accurate in both alinement with the rest of the flapper and at height from the faces of the flapper. If these two conditions are not met, the flapper may bind during operation when it is supposed to float in PCB's and/or it may not properly cover the drain hole (see fig. B-10). (b) The second method is to make a metal or plastic pattern of the flapper valve. The pattern can be used to make a reusable mold out of plastic or metal. Since the flapper valve is symmetric, the two mold halves can be identical in shape. (However, one of the mold halves should have a roughened face so that one side of the flapper valve will also be rough; the roughness will be on the side of the flapper valve that is away from the drain hole, and the purpose of the roughness is to minimize sticking of the flapper valve to the "valve rest" during the period of years that it may lie in the open position. ) Each mold half should look like that shown in figure B-ll. Use parting compound on the mold halves and do so sparingly on the face that is to be smooth. 64 A LENGTH OF #14 TEFLON TUBE CAN BE LAID ACROSS THIS TROUGH BEFORE THE MOLD HALVES ARE CLOSED; IN ORDER TO MAKE SURE THE TUBE REMAINS STRAIGHT, CAST THE SILICONE RUBBER AROUND IT WHILE THE 1/16-INCH BRASS HINGE SCREW IS INSIDE THE TUBE. FIGURE B-ll. - Mold half for pattern of "flapper valve." After casting, cut away the excess rubber (the flash) and (after removing the brass hinge screw) cut the Teflon tube to the proper length — that is, approximately 1/32 inch or 0.030 inch excess tubing on each side of the flapper valve. 12. The flapper is attached to the valve body by means of a brass hinge screw and four Teflon washers measuring 0.020 inch in thickness and with an inside diameter of 1/16 inch and an outside diameter of 1/4 to 3/8 inch. The hinge screw must have the dimensions shown in the diagram below, and the Tef- lon washers must be placed as shown. The nut should be run down tight against the end of the threaded portion of the hinge screw to provide adequate tight- ness of the nut and screw. The final assembly should allow the flapper valve lots of free play (fig. B-12). 13. The filter screen is not to be attached until after the entire valve assembly is in place in the dike. Installation of the valve assembly on the dike should follow this sequence: (a) A 1/2-inch galvanized pipe flange should be cut in the manner shown in figure B-13 so that it can be fitted low on the inside of the steel dike. (b) The drain valve is screwed into the flange tightly, and then the combination of flange and valve is fitted and put into position on the inside of the dike, as shown in figure B-14. NUT TEFLON WASHER (4) FLAPPER VALVE 1/16" D BRASS 1 f (UNTHREADED) HINGE SUPPORT FIGURE B-12. - Hinge support for flapper valve. 65 .*»" 1/8" MIN A T FIGURE B-13. - Pipe flange. IF THERE IS INTEFERENCE AT THIS POINT, DO NOT BEND THE VALVE REST; EITHER MAKE THE VALVE LONGER, OR GRIND METAL OF THE DIKE. ~ FLANGE MUST BE > FLUSH WITH DIKE GUARD PLATE SHOULD /* REST ON MOUNTING PAD FIGURE B-14. - Fitting of drain valve and flange into inside of dike. (c) Remove the flange from the valve and then, after the bolt holes are drilled in the dike, locate and drill the center drain hole in the dike, using the flange to locate the position of the center hole. (Drill a hole of about 3/4-inch diameter, or at least drill a smaller hole that will be positioned so as to allow all water to drain from the valve.) (d) Screw the valve back into the flange tightly and, sealing the face of the flange with silicone rubber caulking compound or some other weatherproof sealant, screw the flange and valve assembly tightly into place on the dike. (e) Additional sealant on the tops of the flange screws and around the edge of the flange will help assure a liquid-tight seal. 66 CRIMP THE SCREEN DOWN TIGHTLY ALONG ALL SURFACES OF THE DIKE AND MOUNTING PAD. FIGURE B- 1 5. - Screen covering valve system. (f) Using brass or stainless steel screen with holes not larger than 1/16 inch on an edge, fabricate the filter screen so that it is bolted into place by the screws that mount into the "guard- plate," and so that it completely covers the valve system all the way down to the concrete and to the bottom and side of the dike. The arrangement for the screen should appear something on the order of that shown in figure B-15. The hold-down screws should be 1/4-20, hex-head copper, brass, or stainless steel. Washers of the same material should be used under the screws and on top of the screen in order to keep the screen from binding and wrapping up on the screws when they are tightened. Bolt holes can be made in the screen by either a punch or by piercing with an ice pick-like tool having a shank diameter of about 1/2 inch or slightly larger. It is imperative that all sides of the valve system be protected by the screen, because the movement of leaves and other particulate matter into the valve area can keep the valve from functioning properly. a93 PC -23 <?U.S GOVERNMENT PRINTING OFFICE: 1981-703-002/25 INT.-BU.OF MINES,PGH.,PA. 25251 . . . _ . /\ l ™ : y% : -SR-v ? v *°™ : . ^ " .0 © *$• V .^'sLf* V o. »• ,G V "'o *^T* A <. .1* * , .* v ^^ ^ -> v 4 o >. oy* 5 ^ 5> vl^L'* *> <* Safe; ^ c *^' *°° <* "> ,6^ f " V'* A > ^ >*\ii»i,\. /.^:-A ^,-^X /,^:X'-.y v^-^ ^ ** DOBBSBROS. ,0^ \3 *7*^ i f>* A iST. AUGUSTINE ^.^ .V^SPT- ^v*' - '^.^ v« ^^'